4 Coastal Marine Ecosystems - rioccadapt
←
→
Page content transcription
If your browser does not render page correctly, please read the page content below
4 Coastal Marine Ecosystems Jorge Cortés (Costa Rica), Alicia Villamizar (Venezuela), Gustavo J. Nagy (Uruguay), Pascal O. Girot (Costa Rica), Karina S.B. Miglioranza (Argentina), and Sebastián Villasante (Spain). This chapter should be cited as: Cortés, J., A. Villamizar, G.J. Nagy, P.O. Girot, K.S.B. Miglioranza, and S. Villasante, 2020: Coastal and Marine Ecosystems. In: Adaptation to Climate Change Risks in Ibero-American Countries — RIOCCADAPT Report [Moreno, J.M., C. Laguna-Defior, V. Barros, E. Calvo Buendía, J.A. Marengo, and U. Oswald Spring (eds.)], McGraw Hill, Madrid, Spain (pp. 123-150, ISBN: 9788448621667).
Chapter 4 – Coastal Marine Ecosystems
CO N T E NTS
Executive Summary......................................................................................................................................................................................................................... 125
4.1. Introduction........................................................................................................................................................................................................................... 125
4.1.1. Conceptual framework...................................................................................................................................................................................... 125
4.1.2. Key figures on coastal marine ecosystems............................................................................................................................................ 126
4.1.3. Coastal marine ecosystems and climate change................................................................................................................................. 128
4.1.4. Previous IPCC reports....................................................................................................................................................................................... 128
4.2. Components of climate change risk in coastal marine environments................................................................................................. 131
4.2.1. Hazards..................................................................................................................................................................................................................... 131
4.2.2. Exposure................................................................................................................................................................................................................... 131
4.2.3. Vulnerability............................................................................................................................................................................................................ 131
4.3. Characterization of risks and their impacts........................................................................................................................................................ 132
4.4. Adaptation measures....................................................................................................................................................................................................... 135
4.4.1. Adaptation options............................................................................................................................................................................................. 135
4.4.2. Planned adaptation activities........................................................................................................................................................................ 135
4.4.2.1. Supranational scale.......................................................................................................................................................................... 137
4.4.2.2. National scale...................................................................................................................................................................................... 137
4.4.2.3. Local scale............................................................................................................................................................................................. 138
4.4.3. Autonomous adaptation activities............................................................................................................................................................. 138
4.5. Barriers, opportunities and interactions............................................................................................................................................................... 138
4.6. Indicators of adaptation effectiveness................................................................................................................................................................. 139
4.7. Case studies ......................................................................................................................................................................................................................... 139
4.7.1. Vulnerability assessment, alternative scenarios and Ecosystem-based Adaptation: Uruguay................................. 139
4.7.1.1. Case summary..................................................................................................................................................................................... 139
4.7.1.2. Introduction to the case problem.............................................................................................................................................. 140
4.7.1.3. Case description................................................................................................................................................................................. 140
4.7.1.4. Limitations and interactions........................................................................................................................................................ 140
4.7.1.5. Lessons learned.................................................................................................................................................................................. 140
4.7.2. Mangrove restoration in El Delgadito, Baja California, Mexico: successful community-based adaptation
to climate change ................................................................................................................................................................................................ 141
4.7.2.1. Case summary..................................................................................................................................................................................... 141
4.7.2.2. Introduction to the case problem.............................................................................................................................................. 141
4.7.2.3. Case description ................................................................................................................................................................................ 141
4.7.2.4. Limitations and interactions........................................................................................................................................................ 142
4.7.2.5. Lessons learned.................................................................................................................................................................................. 142
4.8. Main knowledge gaps and priority lines of action........................................................................................................................................... 142
4.9. Conclusions............................................................................................................................................................................................................................ 143
Frequently Asked Questions...................................................................................................................................................................................................... 143
Acknowledgements.......................................................................................................................................................................................................................... 144
Bibliography ........................................................................................................................................................................................................................................ 144
124 RIOCCADAPT REPORT
Chapter 4 – Coastal Marine Ecosystems
Executive Summary ple, storms and floods, or driven by the effects of sea level
rise. Sustainable management of coastal environments (e.g.
fisheries and aquaculture) contributes to Ecosystem-based
Ibero-America harbors an extraordinary biological diversi- Adaptation by enhancing ecosystem functions and services.
ty and the Latin American and Caribbean region is con-
sidered a superpower in terms of biodiversity, with major Protected marine areas are one of the main mechanisms
long-term economic potential. A significant proportion of for restoring coastal and marine ecosystems. In regions
this biodiversity is found in the coastal and marine ecosys- protected for conservation purposes, the recovery of species,
tems of countries belonging to the Ibero-American Network population abundance and ecosystem functions has been
of Climate Change Offices (RIOCC), including, among others, achieved through the regulated use of marine and coastal
mangroves, estuaries, marshes, seagrass beds, coral reefs, organisms. RIOCC countries have a significant proportion of
macro-algae forests, and deep-sea regions. coastal marine ecosystems under some form of legal protec-
tion, although protection is not actually provided in practice.
Coastal and marine ecosystems of RIOCC countries are
already being affected by direct and indirect human activity Options are available for climate change adaptation in
and by the effects of climate change. Deforestation, soil RIOCC countries. These options include the restoration of
conversion for agriculture, shellfish farming, dam construc- key species and ecosystems for the recovery of ecologi-
tion, large-scale salt mining, and the discharge of polluted cal functions, reestablishment of species and populations
effluents into the sea, among other stressors, exacerbate to increase the resilience of coastal marine ecosystems,
impacts associated with climate change on Latin America’s and Ecosystem-based Adaptation. Projects in several RIOCC
coastal marine environments. countries are focusing on restoring altered ecosystems so
that they may contribute to climate change adaptation and
Ocean temperatures are increasing and some of the con- mitigation. Sustainable fisheries and aquaculture projects
sequences include rising sea levels, changes in the distri- are also available and these could lead to the recovery of
bution, behavior and reproduction of marine species, and ecosystem services.
alterations of ocean current patterns. The results of these
In order to define local, national and regional adaptation
anthropogenic and climate transformations impact ecosys-
actions, further basic research is required to understand
tems by significantly reducing their resistance and resilience,
the current state of ecosystems, the ecosystem services
jeopardizing their capacity to provide goods and services,
they provide, and their responses to observed and projected
and even leading to the extinction of certain species. Severe
future changes. Basic and applied research in RIOCC coun-
impacts on these flows of goods and services for human
tries, especially in Latin America and particularly in marine
well-being are expected, such as, reduced economic benefits
and coastal environments, requires greater and improved
from the migration of catch species, reduced employment,
institutional, governmental and international support. Train-
loss of traditional knowledge of coastal populations, and a
ing of professionals in different areas of basic, social, eco-
decline in the social cohesion of coastal communities, ulti-
nomic and legal sciences is needed to generate the nec-
mately leading to greater inequality in the region.
essary knowledge for maintaining, protecting, conserving,
The impacts of climate change on coastal and marine eco- restoring, and monitoring marine and coastal ecosystems,
systems in RIOCC countries are apparent in a context of their species and ecological functions.
pre-existing vulnerability. Vulnerability originates from human
activities that take place around the coastal marine ecosys-
tems (tourism, unplanned urban expansion, pollution from land-
based sources, and the aquaculture boom). These represent
4.1. Introduction
a threat to fish populations, corals and mangroves. Some of
these impacts, such as coral bleaching in the Caribbean, have 4.1.1. Conceptual framework
already been observed in the region, especially linked to rises
in temperature and the loss of mangrove cover in Latin Amer- Coastal marine environments are defined as those located on
ica. Human activities located in low-lying coastal areas of the the coast with a distinct marine influence, such as estuaries
region also contribute to the increased exposure and vulnera- and mangroves, as well as the marine environment itself, with
bility of human populations to the effects of climate change, both pelagic and deeper environments. They include the lower
such as sea level rise, coastal erosion and tidal swells. end of river watersheds, bays, estuaries and coastal lagoons,
rocky areas, beaches, reefs, continental shelves and slopes,
The sustainable and integrated management of coastal as well as upwelling areas (FAO, 2019). The ecosystem ser-
environments is one of the pillars of Ecosystem-based Adap- vices provided by these environments are key to achieving the
tation, enabling the enhancement of ecosystem functions UN Sustainable Development Goals (SDGs), particularly SDG
and services. Ecosystem-based Adaptation is a common 1 (End Poverty), SDG 2 (Zero Hunger), SDG 6 (Clean Water
practice in marine and coastal areas and is relevant for the and Sanitation), SDG 8 (Decent Work and Economic Growth),
management of mangroves, seagrasses, coral reefs and SDG 12 (Responsible Consumption and Production), SDG 13
sandy beaches. These ecosystems have the natural capac- (Climate Action), and SDG 14 (Life Below Water) (Sherman and
ity to regulate or mitigate impacts generated by, for exam- Hamukuaya, 2016; Claudet et al., 2020).
RIOCCADAPT REPORT 125
Chapter 4 – Coastal Marine Ecosystems
Climate change involves the combined effects of multiple most biologically diverse areas in the world, including coast-
stressors, such as rising sea-surface temperatures, acidifi- al marine ecosystems (Bovarnick et al., 2010). The Ibe-
cation, deoxygenation, and sea-level rise (Figure 4.1). These ro-American region represented by the countries belonging
multiple drivers interact in additive, synergistic, neutral or to the Ibero-American Network of Climate Change Offices
even counteracting ways. Climate multi-stressors cause dif- (RIOCC; http://www.lariocc.es) includes a wide diversity of
ferent impacts on ecosystems (biodiversity decline, species coastal and marine environments, described further below
migration, functional changes), aggravated by local/regional (Table 4.1). Maritime coasts in 19 of the 22 RIOCC coun-
anthropogenic impacts (eutrophication, urban construction, tries exhibit very heterogeneous characteristics, i.e. from
aquaculture, deforestation, and overfishing). tropical to polar environments, and including subtropical and
temperate habitats (Figure 1.12 in Chapter 1). This diversi-
ty extends up along the actual coastal zones and down to
4.1.2. Key figures on coastal marine deep marine regions, which present heterogeneous hydro-
ecosystems graphic and climatic conditions, either regularly exposed to
storms and hurricanes, or completely protected from their
Latin American and Caribbean countries account for more impacts. The differences in coastal geomorphology and
than 40% of the Earth’s biodiversity and are among the hydrographic conditions determine the presence and level
Change in sea level
Warming
Acidification
Shift in currents
Deoxygenation
Figure 4.1. Summary of climate-related hazards in coastal marine environments: [1] intertidal areas (coastal lagoons, rocky areas, sandy beaches,
estuaries, mangroves, and marshes); [2] shallow ecosystems (seagrass beds, coral reefs, rhodolith beds, soft and rocky bottoms); [3] continental
shelf (plankton, benthic communities, pelagic environments, methane seeps), and [4] deep regions (continental slopes, hydrothermal vents,
seamounts, abyssal plains, trenches, pelagic environments). The color gradient refers to depth (darker shades represent deeper regions). Source:
Compiled by the authors.
126 RIOCCADAPT REPORT
Chapter 4 – Coastal Marine Ecosystems
Table 4.1. Major tropical, subtropical and temperate coastal marine ecosystems in RIOCC countries. Source: Compiled by the authors from
the sources cited in the table.
Ecosystem Relevant characteristics References
Sandy beaches and rocky intertidal Important for turtle nesting and tourism; rocky intertidal areas Defeo et al., 2009; Cortés, 2016
areas represent habitats for species used for local consumption.
Soft bottoms Sedimentary areas and habitats for species of ecological and Sibaja-Cordero et al., 2016
commercial interests, such as shrimp and fish.
Mangroves Strategic habitats for biodiversity, high productivity, local and Nava-Escudero, 2008; Polidoro et al.,
commercial fishing resources, erosion control, coastal stabilization and 2010; Martínez et al. 2014; Alongi and
tourism. They act as a carbon sink for greenhouse gases. Thirteen of Mukhopadhyay, 2015; Herrera-Silveira et al.,
22 RIOCC countries have mangroves with a total area of approximately 2016; Feller et al., 2017; Beck et al., 2018
260,000 km2.
Marshes Subtropical and temperate environments of intertidal phanerogams, Idaskin and Bortolus, 2011
featuring high productivity and biodiversity. Significant environments for
coastal protection and carbon sequestration.
Estuaries and coastal lagoons (also Estuaries are environments associated with river mouths to the sea, Medina and Barboza, 2006; Day et al., 2011;
known as albuferas) and coastal lagoons are bodies of water isolated or occasionally Blanco et al., 2012
connected to the sea. They are characterized by a wide gradient of
salinity and temperature, have a high primary productivity, and are
important for fisheries.
Seagrass beds Major and extensive shallow ecosystems in the Caribbean Sea, Hemminga and Duarte, 2000; Mazarrasa et al.,
formed by marine phanerogams. Highly biodiverse sites, extremely 2015, 2018; Cullen-Unsworth and Unsworth,
productive, assist in the elimination of pathogens and have an 2018
important role in carbon sequestration.
Hard or rocky bottoms Hard or rocky bottoms (shallow coastlines typical of high- Villasante, 2009; Wahl, 2009; Macho et al.,
energy environments resulting from intense waves and currents) 2013
possessing great biological diversity and high net primary
productivity.
Rhodolith beds Formed by calcareous algae that grow in a spherical shape, they Amado-Filho et al., 2010; Foster et al., 2013;
are considered highly diverse sites and significant as breeding Cortés et al., 2017
grounds for species that later drift to other marine environments.
Coral Reefs The most diverse marine ecosystems. They form barriers for coastal Birkeland, 2015; Hallock, 2015; Cortés et al.,
protection. are used as artisanal fishing areas and sources of new 2017; Hughes et al., 2017, 2019; Cortés,
chemical-pharmaceutical compounds, and constitute a major attraction 2019a
for tourism in many tropical countries. Corals and reefs contain
excellent paleoclimate records.
Macro-algae forests Highly productive intertidal or subtidal ecosystems at high latitudes; Ríos and Mutshke, 2009; Miller et al., 2018
provide habitat for a great diversity of species. Important for coastal
protection.
Mesophotic regions Mesophotic or low light regions, between 50 and 150 m deep; are Kahng et al., 2014; Cortés, 2019b
being studied as refuges for species displaced by warming of surface
waters.
Pelagic environments Extensive open water, neritic regions on the continental shelf and Da Rocha et al., 2014; Silva et al., 2015
oceanic regions in waters over 200 m deep. Surface zones close to
200 m in the tropics in very clear waters. The world’s main fisheries
operate in neritic regions, especially in upwelling regions, and are
increasingly moving toward deeper areas (tuna, Iberian sardine).
Abyssal trenches and plains Abyssal trenches and plains are scantly studied environments given Levin and Le Bris, 2015; Levin et al., 2016;
the difficulties in working at depths of 1,000 meters or more. These Llatas et al., 2018
areas should be researched and explored, as both fishing and mineral
exploitation is being conducted in increasingly deeper waters; moreover,
the impact of climate change on these areas is little-known.
of development of certain benthic or pelagic communities in the diversity and productivity of coastal marine systems
(coral reefs, pelagic fish, among others). The presence of due to the continent’s contribution of nutrients (Escobar-Bri-
surface freshwater aquifers and river discharge are some ones et al., 2015; Torres-Bejarano and Torres-Marchena,
of the ecological drivers that will also determine changes 2017; Villamizar and Cervigón, 2017; Canty et al., 2018).
RIOCCADAPT REPORT 127Chapter 4 – Coastal Marine Ecosystems
In general, land uses in basins that influence the coastal 4.1.3. Coastal marine ecosystems
zone are also stressors that, in synergy with the impacts of
climate change, can compromise the health of ecosystems and climate change
and consequently the ecosystem services they provide and,
ultimately, their resilience and adaptive capacity to climate The most significant impacts on coasts stemming from the
effects of long-term climate change are linked to rising sea
effects, natural or induced (Deutsch et al., 2007).
levels, rise in sea surface temperatures, acidification, chang-
The coastal region of RIOCC countries extends across 13 es in salinity, waves, tides, and extreme events (Table 4.4).
biogeographic sub-provinces (Figure 1.12 in Chapter 1), with These impacts can potentially cause, among other occur-
a wide diversity of coastal marine ecosystems due to their rences, erosion and flooding problems, impacts on port,
climatic, oceanographic and geographic specificities (Milo- urban, industrial and tourism infrastructure, coral bleaching,
slavich et al., 2011, 2015) (Table 4.1). The region, which is and alterations to the flow of sediments and to biodiversity
large in size and latitudinally wide, covers the 19 countries (ECLAC, 2012, 2015).
with marine coasts and presents differentiated character-
Since the Second Assessment Report of the Intergovern-
istics in terms of bathymetry, hydrography, productivity,
mental Panel on Climate Change (IPCC), potential impacts
oceanographic and climatic processes (FAO, 2012; Botello
of climate change on marine and coastal biodiversity have
et al., 2017). The coastal marine ecosystems existing in this
been identified on a global scale (Bijlsma et al., 1996). Sig-
vast territory have been grouped as tropical (five regions)
nificant trends in precipitation and temperature observed in
or temperate (eight regions), highlighting their ecosystemic
Latin America and changes in climate variability and extreme
diversity, the ecosystem services they provide and sustain,
events demonstrate that the coastal region has been severe-
and providing local and regional examples of select repre-
ly affected (Magrin et al., 2014; Bidegain et al., 2018). There
sentative ecosystems.
is evidence for Latin America and the Caribbean of warming
Of the 22 countries grouped in RIOCC (Figure 1.1 in Chap- between 0.7°C and 1°C (in the last 30 to 50 years), except
ter 1), 15 (68.2%) have tropical coastal marine environ- for the west coast of South America, from Peru to Chile,
ments in the Tropical Eastern Pacific (Colombia, Costa where temperatures have cooled by -1°C during the same
Rica, Ecuador, El Salvador, Guatemala, Honduras, Mexico, period. On the extremely arid coast of northern Chile, rain,
Nicaragua, Panama and Peru), in Easter Island (Chile), in temperature and cloudiness show strong inter-annual and
the Tropical Western Atlantic (Colombia, Costa Rica, Cuba, decadal variability since the mid-1970s (Magrin et al., 2014).
Dominican Republic, Guatemala, Honduras, Mexico, Nicara-
gua, Panama and Venezuela), and in the northern Brazilian
plateau (Brazil and Venezuela). Additionally, 36.4% (8 coun- 4.1.4. Previous IPCC reports
tries) have coastal marine environments in subtropical or
temperate zones, such as in the warm temperate Northeast The IPCC Special Report on the Ocean and Cryosphere in
Pacific (Mexico), the warm temperate Southeast Pacific a Changing Climate (SROCC) (2019) focuses on climate
(Chile and Peru), the Magellanic province (Chile and Argen- change impacts on oceans. The impact of sea level rise is
tina), the warm temperate Southwest Atlantic (Argentina, exacerbated by the combination of other climate events (hur-
Brazil and Uruguay), the warm Northwest Atlantic (Mexico), ricanes, tidal waves, El Niño) and by the degradation of the
the Lusitanian province (Spain and Portugal), and the Med- coastal zone by human activity. This will result in the loss
of biodiversity and ecosystem functionality, a reduction in
iterranean Sea (Spain).
the area of mangroves in most cases due to the inability
A significant proportion of RIOCC countries’ coastal marine of these ecosystems to migrate inland, and a possible lim-
environments receive some form of legal protection (OAS, itation in the resistance and resilience of coastal marine
2008; De Oliveira-Miranda et al., 2010; Garcia et al., ecosystems (IPCC, 2019). The recovery capacity of coastal
2011; CPPS/UNESCO/CI/Hivos, 2015), which additionally marine ecosystems will decrease owing to the exposure to
represents another advantage over climate change. Per- increasingly intense and recurrent climatic and non-climatic
centages of protected coastal marine areas vary widely in impacts. However, it is possible to adapt to such changes
RIOCC countries (Table 4.2). The fact that coastal marine by mitigating these impacts through a less destructive use
territories of RIOCC countries receive some form of protec- of coastal areas and their ecosystems, protecting existing
tion translates into a legal condition that could facilitate the ones, restoring ecosystems, and creating new marine pro-
inclusion of climate change adaptation measures. More- tected areas based on scientific evidence (Carr et al., 2019).
over, there are regional institutions and adaptation and mit- Another notable issue brought up by the SROCC is the fact
igation initiatives that have recently increased awareness that coastal retreat is already occurring in many countries.
of the importance of the ecosystem services of coastal In Latin America, coastal retreat has been recorded in Gua-
marine resources, and the risk that climate change rep- temala, the Costa Rican Caribbean, and western Colombia.
resents for their preservation and their economies. Diverse Saline or brackish water intrusion driven by sea level rise
initiatives have also emerged aimed at defining adaptation in combination with tidal waves and human-induced sinking
and mitigation measures within the RIOCC framework for leads to an increase in residual salinity, as already recorded
action (Table 4.3). in the Ebro Delta, Spain (Magnan et al., 2019).
128 RIOCCADAPT REPORTChapter 4 – Coastal Marine Ecosystems
Table 4.2. Marine protected areas in Latin America and the Iberian Peninsula. Sources: Compiled from FAO (2015) and Protect Planet (2018),
and supplemented by the authors.
Land and Marine Marine % protected
Total Land Total Marine # of % of marine
Country # of PAs Protected Area Protected of the entire
Area (km2) Area (km2) MPAs area of PAs
(km2) Area (km2) marine area
Argentina 2,785,328 1,083,151 458 363,373 43 127,462 35,07 11,77
Brazil 8,529,321 3,672,584 1,515 3,487,114 274 977,793 28,04 26,62
Chile 759,821 3,657,313 211 1,661,657 33 1,506,502 90,66 41,19
Colombia 1,141,748 928,680 56 294,282 14 124,737 42,39 13,43
Costa Rica 51,636 576,110 187 19,055 24 4,802 25,20 0,83
Cuba 111,643 365,756 105 34,300 57 15,819 46,12 4,33
Dominican Republic 258,139 1,079,901 45 200,105 17 144,125 72,02 13,35
Ecuador 20,753 94,238 118 2,471 4 665 26,91 0,71
El Salvador 507,013 1,005,717 1,863 226,517 14 84,220 37,18 8,37
Guatemala 109,922 118,336 305 23,104 7 1,065 4,61 0,90
Honduras 113,291 219,971 91 36,204 16 9,144 25,26 4,16
Mexico 1,965,285 3,284,660 174 1,000,442 63 715,465 71,51 21,78
Nicaragua 129,222 223,935 72 33,305 8 7,895 23,71 3,52
Panama 75,498 332,643 89 21,366 43 5,593 26,18 1,68
Peru 1,298,537 838,330 134 280,809 3 4,037 1,44 0,48
Portugal 92,141 1,724,156 166 306,689 8 285,588 93,12 16,56
Spain 48,510 270,774 123 61,352 33 48,625 79,25 17,96
Uruguay 178,460 130,098 11 7,082 8 932 13,16 0,72
Venezuela 917,368 473,325 400 513,201 49 16,500 3,21 3,49
Table 4.3. Regional institutions and initiatives for adaptation and mitigation in the coastal marine zone implemented in RIOCC territories. Legend:
CC: Climate Change; SD/SDG: Sustainable Development/Sustainable Development Goals; REDD: Reducing Emissions from Deforestation from
Developing Countries (UN Program); EcoCC: Economics of Climate Change; Biodiv: Biodiversity. The symbol X indicates issues addressed by each
institution. Sources: Compiled by the authors from www.celac.org; www.oei.es/en; www.sica.int; www.oas.org; www.caricom.org; www.aladi.org;
www.parlatino.org; www.unasursg.org; www.oecs.org; www.parlacen.int.
Institution CC SD/SDG REDD EcoCC Biodiv
Community of Latin American and Caribbean States (CELAC) X X X
Organization of Ibero-American States for Education, Science and Culture (OEI) X
Central American Integration System (SICA) X X X
Alliance for Sustainable Development (ALIDES) X
Organization of American States (OAS) X
Caribbean Community (CARICOM) X X X X X
Latin American Integration Association (LAIA/ALADI) X
Latin American and Caribbean Parliament (PARLATINO) X
Union of South American Nations (USAN/UNASUR) X X X
Organization of Eastern Caribbean States (OECS) X X X
Central American Parliament (Parlacen) X
Universities and research centers X X X X X
ECOMAR Network X X X
National Climate Councils X X X X X
RIOCCADAPT REPORT 129Chapter 4 – Coastal Marine Ecosystems
Table 4.4. Climate stressors and main extreme events on the region’s coasts. Sources: Compiled by the authors from Peel et al. (2007), Calil
et al. (2017), Nagy et al. (2018).
Country Climate stressors and main extreme events in coastal areas
Argentina El Niño, storms, river flooding, coastal flooding, sea level rise
Brazil El Niño, extra-tropical cyclones, river flooding, sea level rise, ocean acidification
Chile El Niño, river flooding, tidal swells, sea level rise
Colombia El Niño, river flooding, sea level rise, ocean acidification
Costa Rica El Niño, storms, river flooding, coastal flooding, sea level rise, ocean acidification
Cuba Hurricanes, storms, sea level rise, ocean acidification
Dominican Republic Storms, hurricanes, sea level rise, ocean acidification
Ecuador El Niño, river flooding, coastal flooding, sea level rise, ocean acidification
El Salvador El Niño, hurricanes, river flooding, sea level rise, ocean acidification
Guatemala Hurricanes, river flooding, sea level rise, ocean acidification
Honduras Hurricanes, river flooding, sea level rise, ocean acidification
Mexico El Niño, hurricanes, storms, river floods, sea level rise, ocean acidification
Nicaragua Hurricanes, river flooding, sea level rise ocean acidification
Panama El Niño, storms, river flooding, coastal flooding, sea level rise, ocean acidification
Peru El Niño, storms, river floods, sea level rise
Portugal Storms, river floods, sea level rise
Spain Storms, river floods, sea level rise
Uruguay El Niño, storms, river flooding, coastal flooding, sea level rise
Venezuela El Niño, river flooding, sea level rise, ocean acidification
The SROCC also provides evidence that it is likely that ocean fied algae) are particularly sensitive to ocean acidification
warming has continued in the abyssal zone and in the deep and the effects of rising temperatures, sea level rise, and
ocean below 2000 m, particularly in the southern hemi- increased extreme events, making these ecosystems highly
sphere and the Southern Ocean. There is also increasing evi- vulnerable (with low resilience) to further warming scenarios.
dence that the ocean carbon sink is dynamic on decadal time In addition, almost all coral reefs will significantly decline,
scales, especially in the Southern Ocean, affecting ocean even if global warming remains below 2°C. Any coral reef that
carbon sequestration on a global scale (medium confidence). survives to the end of the century will not be the same due
It is virtually certain that surface ocean pH will decline by to irreversible changes in habitat structure and functioning,
0.036-0.042 or 0.287-0.290 pH units by 2081-2100, rela- including species extinctions and food network disturbances;
tive to 2006-2015, for the RCP 2.6 or RCP 8.5 scenarios, these changes are already occurring (Hughes et al., 2017).
respectively. These pH changes are very likely to cause the Conversely, ecosystems with strong influences of physical
Southern Oceans to become corrosive for the major mineral factors (e.g., sediment accretion and subsidence) present
forms of calcium carbonate under RCP 8.5, but these chang- no change in their vulnerability to sea level rise, suggesting
es are avoidable under the RCP 2.6 scenario (Bindoff et al., a strong resilience in some coastal ecosystems. However,
2019). Recent evidence suggests that mesophilic coral reefs in areas such as the Caribbean, mangroves cannot exceed
will be affected by ocean acidification. All coastal ecosys- current rates of sea level rise and may disappear. The tran-
tems will be at high to very high risk by the end of the 21st sition to new states by unpredictable pulses of progressive
century under the RCP 8.5 scenario, especially coral reefs climate disturbances and hazards will have adverse impacts
(transitioning from high to very high risk 0.6-1.2°C), seagrass on ecosystem services (Bindoff et al., 2019).
beds (2.2-3.0°C), kelp forests (2.2-2.8°C) and rocky shores
(2.9-3.4°C). These ecosystems have low or moderate adap- Adaptation responses to climate change are most effec-
tive capacity, rendering them highly sensitive to ocean warm- tive when developed within institutional frameworks that
ing, sea heat waves, and acidification. For example, kelp include effective planning and inter-sectoral integration. Evi-
forests and seagrass beds will continue to decline with more dence-based decision making for climate adaptation is strong-
frequent extreme temperatures and their low dispersal capac- ly supported in the literature by an enhanced understanding
ity will increase the risk of local extinction. Shallow biogenic of coastal ecosystems and human adaptation responses,
reefs with calcified organisms (e.g., corals, mussels, calci- as well as the consideration of non-climate change drivers.
130 RIOCCADAPT REPORTChapter 4 – Coastal Marine Ecosystems
Relevant research includes participatory planning, cross-bor- impacts such as eutrophication, have led to an expansion of
der ocean management, and ecosystem-based and com- anoxic regions and increased hypoxia in oceans, while the
munity-based adaptation. Fresh knowledge of climate and dissolution of CO2 in the oceans is lowering the pH (ocean
non-climate variables in coastal adaptation planning could acidification). This change in ocean chemistry impacts living
substantially improve planning, implementation and monitor- organisms, altering their calcification, life cycles, and behav-
ing of climate adaptation responses for marine systems, if ior (Hoegh-Guldberg et al., 2007; Baker at al., 2008; Vergara,
research processes are participatory and inclusive. 2009; Gatusso and Hansson, 2011; Schmidtko et al., 2017;
Palter et al., 2018; Hughes et al., 2019).
Integrated adaptation planning in many countries is under-
mined by uncoordinated, top-down approaches, lack of polit- There is evidence indicating that sea level change and non-cli-
ical will, insufficient resources and access to information. mate stressors generate hazards to fisheries, corals, man-
Successful adaptation frameworks include: a robust but flex- groves, tourism and recreation, and disease control in the
ible approach that takes into account the increasing uncer- coastal region (Olivo et al., 2012; Godoy and de Lacerda,
tainty; well-coordinated participatory processes; and well-de- 2015). Sea level change is largely due to the thermal expan-
veloped monitoring systems that adopt a complete systems sion of water and the inflow of water from the continents as
approach, identifying additional benefits for human develop- a result of glacier and polar ice melting. Sea levels are rising
ment and the environment. The literature on coastal adap- rapidly, from 1.4 mm per year in the 1901-1990 period to
tation is less studied in Africa and in the Caribbean. Unlike 3.2 mm per year between 1993 and 2015, and 3.6 mm per
many examples of proposed frameworks for climate-resilient year in the 2005-2015 period (IPCC, 2019). In Latin America
coastal adaptation, few studies have assessed their suc- and the Caribbean, sea level change has been increasing
cess, possibly due to the delay between implementation, from 2 to 7 mm per year over the past 60 years (Magrin et
monitoring, evaluation and reporting. More effective coordi- al., 2014). Recurrent episodes of coral bleaching linked to
nation among relevant actors and stakeholders, within and ocean warming and acidification have also been recorded
between organizations, especially in developing countries, along the Caribbean and Colombian Pacific coasts (Rojas
would strengthen the global response to coastal adaptation Higuera and Pabón-Caicedo, 2015), in the Mesoamerican
(Oppenhaimer et al., 2019). coral reef corridor, and in the southern Caribbean (Villamizar
and Cervigón, 2017). However, available information on sea
level change in the region is limited, lacking sufficiently long
4.2. Components of climate series, except in Buenos Aires and Montevideo; therefore,
predicting its actual impact is difficult (Nagy et al., 2019).
change risk in coastal
marine environments 4.2.2. Exposure
Most of the region’s coastal areas are exposed to climate
4.2.1. Hazards change, ENSO variability, and extreme weather events (sea
level rise, tidal waves and waves). Because of their geo-
Rising ocean temperatures modify the distribution of marine graphical location, the risk is higher in low-elevation coastal
species and cause rising sea levels (IPCC, 2014; Uribe-Bote- zones (LECZ), including ecosystems, cities and infrastructure
ro, 2015; Villamizar and Cervigón, 2017). The combination (Villamizar et al., 2017; Calil et al., 2017; Nagy et al., 2019).
of these drivers adversely affects megadiverse ecosystems Due to these hazards to coastal marine ecosystems, coastal
such as coral reefs, clearly manifested through coral bleach- environments and their ecosystem services, coastal human
ing and diseases in reef species. Changes also affect the populations and economic activity will be affected. Coastal
structure and function of kelp forests (Bas Ventín et al., marine ecosystems supply a series of services including
2015) and increase the likelihood of toxic algal blooms (Ama- food supply, water purification, wave protection, and rec-
do-Filho et al., 2010; Cróquer et al., 2018; Outeiro et al., reation. The loss of these ecosystem services will impact
2018). The years 2005 and 2010, recognized by the NOAA coastal communities through coastal erosion, salinization
as the hottest years in recent decades in the Caribbean, saw of aquifers, loss of landscape, safe docking, and changes
bleaching events affecting coral reefs (Eakin et al., 2010; in fisheries. These effects will impact other economic areas
Cróquer et al., 2018). Most of the coral reefs in Morrocoy such as tourism and fishing, jeopardizing the well-being of
National Park and Los Roques (two of the most important individuals, communities, regions and countries of RIOCC.
coastal marine protected areas in Venezuela) were affected
in the 2005 event, however, “they eventually recovered, with-
out the stress period ending in mass mortalities” (Villamizar 4.2.3. Vulnerability
et al., 2014).
An ecosystem’s vulnerability is determined by its likelihood
Changes in temperature and salinity are causing alterations of experiencing climate change impacts and its resilience,
in current patterns, which will affect the dispersion and dis- which determine how, and how quickly, it recovers from these
tribution of species. These changes, along with direct human impacts (IPCC, 2014). The resilience and resistance of natu-
RIOCCADAPT REPORT 131Chapter 4 – Coastal Marine Ecosystems
ral systems, in turn, enhance their capacity of autonomous Table 4.5. Ranking of RIOCC countries in the Global Ocean Health
adaptation (Klein and Nicholls, 1999). Human intervention, Index. A lower ranking indicates healthier seas. Source: Compiled by the
particularly through integrated coastal zone management authors from http://www.oceanhealthindex.org; revised June 24, 2019.
and adaptation measure planning, can improve ecosystems’
capacities to respond to and recover from the impacts of Country Ranking
extreme climate events, as well as to adapt to changing Portugal 25
local conditions (BIOMARCC-SINAC-GIZ, 2013). In bioregional Chile 54
conservation approaches, the emphasis in prioritizing pro-
Cuba 87
tected areas for in situ conservation lies on the representa-
tion of relevant ecosystem samples to ensure their perma- Ecuador 65
nence over time (Miller, 1996; Andrade et al., 2011). In the Argentina 93
case of climate change, representativeness and ecosystem Mexico 97
conservation as criteria for the creation of protected areas
should be supplemented by approaches such as the search Spain 104
for redundancy in the representation, as permanence will be Brazil 124
affected in many ecosystems, particularly in coastal zones. Honduras 125
The resilience to climate impacts of protected areas is deter-
Dominican Republic 129
mined by the adaptive capacity of species and their connec-
tivity in landscapes and seascapes (Barber et al., 2004). Panama 132
The vulnerability of built structures depends on society’s Uruguay 146
intrinsic ability to prevent, live or cope with climate change Costa Rica 154
impacts, in particular its capacity for adapting at the same Venezuela 171
rate as the natural systems on which they depend (Klein and
Guatemala 181
Nicholls, 1999; Klein et al., 1999). These local development
conditions are determined by the population’s socio-econom- Peru 188
ic and health circumstances, its local environment (acces- Colombia 192
sibility, employment, environmental quality), and the local El Salvador 203
institutional capacities to provide continuity of public services
(Retana et al., 2017). Therefore, to a large extent, priorities Nicaragua 219
for adaptation in coastal areas must be defined taking into
account the limitations and potential of the local context.
Adverse coastal and marine impacts and vulnerability lead The fourth IPCC report (IPCC, 2007) observed, and the Spe-
to losses that pose significant challenges and costs to soci- cial Report on Oceans and Cryosphere (IPCC, 2019) later
eties, particularly in developing countries (Hoegh-Guldberg reaffirmed, with a high level of confidence, that some unique
and Bruno, 2010). For example, the Ocean Health Index and threatened systems are already at risk from climate
(Halpern et al., 2012) measures the integration and health change and that this risk will increase if additional warming
of the human-ocean system for each country and includes of around 1°C occurs. The situation will be graver still for
parameters related to climate change. The index includes key many species and systems with limited adaptive capacity,
elements of ocean health: biological, physical, economic and i.e. coral reefs (Wang et al., 2017). The SROCC also warns
social, for the purpose of informing decisionmakers on how that the risk level of serious impacts on biodiversity and the
to manage ocean sustainably (http://www.oceanhealthindex. structure and function of coastal ecosystems will be higher
org). Values of RIOCC countries range from very favorable, due to increased temperatures associated with higher emis-
e.g. Portugal, to very unfavorable, e.g. some Central Ameri- sion scenarios (~1760 ppm CO2 RCP 8.5), compared to lower
can countries (Table 4.5). emission scenarios projected for the 21st century (~490
ppm CO2 RCP 2.6). Sea level projections display regional
differences around the global average level. Processes such
as local sinking caused by natural phenomena and human
4.3. Characterization of risks activities are important for relative sea level changes on the
coast. While the relative importance of climate-driven sea
and their impacts level rise is expected to increase over time, there is a need
to consider local processes within sea level projections and
In addition to the observations outlined in Section 4.1.3, cli- impacts. Lack of continuity in public management, fluctua-
mate risk in coastal areas is also the outcome of a combination tions in national economies, dependence on fossil fuels and
of biophysical drivers with socio-cultural, economic and institu- accelerated urban growth in Latin America and the Caribbean
tional drivers that can generate major and permanent impacts have complicated the consolidation of effective environmen-
on marine life and on the well-being of human populations that tal management of the coastal zone. As a result, the risk
live in and depend on healthy ecosystems for their livelihood. of loss of biodiversity and key ecosystems for the provi-
132 RIOCCADAPT REPORTChapter 4 – Coastal Marine Ecosystems
sion of ecosystem services increases, both inside and out- cover, permafrost and fresh/marine water, with effects on
side coastal protected areas (Yerena et al., 2018). Climate the quality of habitat, areas of distribution, phenology and
change is expected to be a significant driver to further deg- productivity of species, as well as on their dependent econ-
radation of most coastal ecosystems, biodiversity and eco- omies, which will affect the southern regions of the South
system services in Latin America and the Caribbean (IPBES, American continent (IPCC, 2014).
2018), resulting in an adaptation deficit for coastal areas in
Potential impacts on Latin America and the Caribbean include
the region (Nagy et al., 2019). On the other hand, it is esti-
floods linked to sea level change for which the probabili-
mated that 100 to 300 million people living in coastal areas
ty of flooding is estimated to be higher in locations show-
worldwide will face greater risks due to the loss of protection
ing > 40% change over the last 60 years in total sea level
provided by marine and coastal ecosystems (IPBES, 2018).
(not including hurricanes); beach erosion in locations where
In terms of the coastal and marine resources of RIOCC coun- potential sediment transport and seaports have increased;
tries, the recent warning of risks associated with a rise in the and threaten the reliability of coastal structures (Magrin et
average temperature of the planet above 1.5°C, as reported al., 2014). For Latin America, climate change risks for coastal
by the IPCC (2018), anticipates a greater hazard. Not exceed- marine environments will be exacerbated by pollution, land
ing 1.5°C is conditioned by the greenhouse gas emissions use, flooding, erosion and urban, industrial and tourist devel-
trajectory and, consequently, by the economic development opments emerging along the region’s coasts (Magrin et al.,
model that the global society decides to follow. Keeping the 2014). Among climate change-related risks, there are con-
rise in temperature below 1.5°C would mean a slower sea lev- cerns about the increase in coral bleaching in the Caribbean
el rise rate that would allow for greater opportunities for the (Bastidas et al., 2012), coupled with an evident limitation of
adaptation of ecosystems in small island territories, low-lying corals for autonomous genetic adaptation. A sharp degrada-
coastal areas and deltas, while at the same time offering a tion of mangroves, wetlands, corals and seagrasses in the
greater likelihood of managing and restoring natural coast- region’s island territories and in continental South America
al ecosystems and strengthening infrastructure. Hazards has direct effects on their economies (Villamizar et al., 2016;
include changes in the distribution patterns of many marine Wilson, 2017; ECLAC, 2018; Gaines et al., 2019; Murray et
species at higher latitudes and increased damage to many al., 2019). The degradation of groundwater and freshwater
ecosystems, as well as further declines of coastal resources ecosystems due to saline intrusion from sea level change
and reduced productivity of fishing and aquaculture (espe- also poses a risk, in addition to degradation due to pollution
cially at low latitudes). Coral reefs are projected to shrink and groundwater extraction (Carson et al., 2016).
their live coral cover by 70-90% at 1.5°C, with higher losses
Impacts generated from non-climate stressors that compromise
(> 99%) at 2°C. Record temperatures in 2015-2016 led to the
the health and existence of coastal ecosystems in Latin Ameri-
largest coral bleaching episode since mass bleaching was
ca and the Caribbean include the loss of mangroves as a result
documented in the 1980s (Hughes et al., 2017). Some indig-
of deforestation and the conversion of soils for agriculture and
enous peoples and local communities that depend on agricul-
shrimp farming (FAO, 2016). In Ecuador, for example, between
ture or coastal livelihoods represent the most disadvantaged
2008 and 2014, 47,000 hectares (ha) of mangrove forests
and vulnerable populations, with a disproportionately higher
were converted to other uses, mainly agriculture. The coun-
risk of adverse consequences with a global warming of 1.5°C
try’s Ministry of the Environment stated that the figure is high;
(Allison et al., 2009; IPCC, 2018; 2019).
however, deforestation has been reduced by 49% (MAE, 2014).
According to projections from integrated climate models In Colombia, Costa Rica, Nicaragua, and Venezuela, nearly a
(IPCC, 2014), known as Representative Concentration Path- third of the population lives in coastal areas directly exposed to
ways (RCPs), by mid-century it will be feasible to detect the climate events. In Nicaragua and Honduras, a high percentage
global redistribution of marine species and the reduction of households use firewood for cooking; the largest amount of
of marine biodiversity in vulnerable regions, which would firewood is extracted from the mangrove, and according to the
adversely impact fishing productivity and other ecosystem FAO (2015) approximately 120,000 m3 of wood is extracted
services. Spatial relocation of marine species due to project- per year for firewood in both countries. In Venezuela, the con-
ed warming will lead to invasions at high latitudes and high struction of dams and large-scale salt mining within protected
rates of local extinction in the tropics and semi-enclosed coastal areas has resulted in the diversion of freshwater flow
seas. The progressive expansion of areas with low oxygen to the mangrove, a habitat of the endangered coastal caiman
levels and anoxic “dead zones” will further limit fish habitat (Crocodylus acutus) (Villamizar, 2003; Rodríguez et al., 2010;
(Breitburg et al., 2018). A total of 400 areas of hypoxia in Nagy et al., 2019). In Galicia (Spain), pollution from agricultur-
the seas have been reported worldwide, generating dead al activities and the construction of reservoirs are causing a
zones covering more than 245,000 km2 (IPBES 2018). Net reduction in the abundance of key commercial species (slimy,
primary production in the high seas will be redistributed fine and blonde clams) for the development of shellfish pick-
and, by 2100, will decrease globally in all RCP scenarios ing, an activity that provides direct employment to more than
(IPCC, 2014). By 2100, ocean primary productivity will have 4,500 women in the region, the highest figure in Europe (Pita
declined by 3-10% and marine fish biomass will be reduced et al., 2019). Table 4.6 presents examples of threatened eco-
by 3-25% due to climate change (IPBES, 2018). Key risks systems, climate change-related impacts, vulnerabilities, and
include those stemming from changes in ice conditions, snow risks in select RIOCC countries.
RIOCCADAPT REPORT 133134
Table 4.6. Examples of threatened ecosystems, climate change-related impacts, vulnerabilities, and risks in select RIOCC countries. Source: Compiled by the authors from various sources.
Country/Source Threatened ecosystems Impacts Vulnerabilities Risks
Argentina Lower Paraná River Delta Due to rising sea levels: flooding Hydrological and climatic regulation Susceptible to industrial, urban and agricultural
Wetlands (Insular; advancing delta front). and displacement of wetlands and (floods); carbon sinks; livelihood of pollution; erosion and marshalling; change in
RIOCCADAPT REPORT
International and low coasts; coastline erosion and fishermen; livelihood of reed gatherers communities due to rising sea levels; fires; loss of
DCCSADS (2010) retreat and increased storm flooding; and otter hunters; water supply for urban biodiversity due to land-use modifications; invasion of
increased salinity in estuaries and areas; biogeographical and ecological non-native species; alteration of local water regime due
hazard to aquifers; alteration of tidal specificities; relevant species for to the construction of canals and dikes.
range in rivers and bays; alteration conservation (marsh deer, dusky-legged
Chapter 4 – Coastal Marine Ecosystems
of sedimentation patterns; and Guan, giant otter); beekeeping activities
reduced amount of light received by (native flora).
the seabed.
Colombia Cartagena Bay Loss of numerous islands and Presence of living corals on Isla Arena, Increased exposure of the coastline and low-tide lands
Andrade Armaya (Natural systems protecting the extensive mangrove areas. west of Pueblo Nuevo, Bolívar, where of Cartagena to systematic, gradual and constant
et al. (2017) coastline). coral communities are growing despite flooding, much faster than the global average, as a
adverse conditions of high sedimentation result of sea level rise due to global warming and land
associated with materials brought by the subsidence.
Magdalena River.
Costa Rica Térraba-Sierpe Delta Significant changes in the river- Meander channels in which mangrove Rising sea levels threaten to increase the erosion rate
Acuña-Piedra and (Aquifers, groundwater, beach marine system morphology. vegetation prevails. of coastal bars, constant geomorphological processes
Quesada-Román texture, mangroves, fisheries, alternating with sedimentation in this deltaic system
(2016) biodiversity). over the last six decades, due to climate variability and
changes in land use in the basins that feed coastal
dynamics.
El Salvador MAP Los Cóbanos, home to El Reef ecosystems are being Two coral bleaching events of considerable Increase in temperature and variability of accumulated
Chicas-Batres et Salvador’s single coral reef. monitored by the Coral and Rock intensity occurred simultaneously with the annual precipitation recorded in the country, compared
al. (2015) Other threatened coastal Reef Program, carried out by the high temperature caused by the El Niño to recent decades.
ecosystems along the country’s Institute of Marine Sciences and phenomenon (2014 and 2015, between Increase in saline intrusion in certain locations in
coast: estuaries, coastal Limnology (ICMARES), Universidad de 80%-100% respectively of the surface of the coastal zone, due to the lack of plant cover, the
lagoons, mangroves, sandy El Salvador. the colonies, and a loss of coverage of emptying of aquifers and reduced land drainage.
and rocky beaches, near-shore about 10% in 2014).
agricultural crops.
Guatemala South Pacific Coast. Region constantly affected by floods Firewood extraction, coal processing, Traditional agricultural export activities may present
Government Aquaculture, agriculture, fishing, and river overflows. construction materials, and gathering of conflicting interests and disagreements over the
of Guatemala mangroves, pastures, wetlands. coast-related fauna-derived products. conservation of biodiversity in the coastal zone.
(2011)You can also read
