East Brazil Shelf
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LME 16: East Brazil Shelf

Bordering country:

Brazil

LME total area:

1,073,210 km²

LME overall risk:

This LME falls in the cluster of LMEs that exhibit low to medium levels of economic development (based on the night light development index) and medium levels of collapsed and overexploited fish stocks.
Based on a combined measure of the Human Development Index and the averaged indicators for fish & fisheries and pollution & ecosystem health modules, the overall risk factor is high.

Productivity

Chlorophyll-A:

The annual Chlorophyll a concentration (CHL) cycle has a maximum peak (0.107 mg.m^-3) in June and a minimum (0.0713 mg.m^-3) during December. The average CHL is 0.0874 mg.m^-3. Maximum primary productivity (146 g.C.m^-2.y^-1) occurred during 1999 and minimum primary productivity (119 g.C.m^-2.y^-1) during 2013. There is a statistically insignificant decreasing trend in Chlorophyll of -3.58 % from 2003 through 2013. The average primary productivity is 133 g.C.m^-2.y^-1, which places this LME in Group 1 of 5 categories (with 1 = lowest and 5= highest).

Primary productivity:

Sea Surface Temperature:

From 1957 to 2012, the East Brazil Shelf LME #16 has warmed by 0.59°C, thus belonging to Category 3 (moderate warming LME). The thermal history of the East Brazil Shelf has been quite non-uniform. The absolute maximum SST of 27.5°C was reached in 1998, after which SST decreased down to 26.9°C in 2012. The most significant events since 1957 were the SST drop down to 26.3°C in 1981 and the 1°C warming between 1981-84, the latter being similar to and largely concurrent with the South Brazil Shelf warming. The above-noted synchronism is however mostly limited to the early 1980s cold spell. Otherwise, the thermal histories of the South and East Brazil Shelf LMEs (respectively #15 and #16) correlate poorly. Divergent currents east of Brazil explain this discordance. Alongshore currents off the Brazilian coast flow in opposite directions, due south/southwest in the South Brazil Shelf LME and due northwest in the northern part of the East Brazil Shelf LME.

Fish and Fisheries

The fisheries of this LME are mainly artisanal, although commercial fisheries for lobster, shrimp and southern red snapper are significant in the states of Ceará, Rio Grande do Norte and Espírito Santo. Tuna (mainly bigeye) are fished in offshore areas and landed mainly in Rio Grande do Norte and Paraíba.

Annual catch:

Total reported landings in the LME increased to 300,000 tonnes in 1973 with Brazilian sardinella (Sardinella brasiliensis) accounting for two-thirds of the landings, but have declined over the past three decades, recording 130,000 tonnes in the recent years. However, a large quantity of fish bycatch from shrimp trawlers is not included in the underlying statistics.

Catch value:

The value of the reported landings peaked at 840 million US$ (in 2005 real US$) in 1973, with landings of crustaceans accounting for the large share.

Marine Trophic Index and Fishing-in-Balance index:

The MTI has remained level at around 3.1 until the late 1990s, when it shifted to around 3.3. Such a shift is likely due to the large decline in the landings of low trophic Brazilian sardinella recorded from 1997 to 1999. As for the FiB index, the expansion of the fisheries in the 1950s and 1960s is represented by an increase in the FiB index, though it has since been on a generally declining trend.

Stock status:

The Stock-Catch Status Plots indicate that nearly 50% of commercially exploited stocks in the LME are either overexploited or have collapsed. A similar interpretation can also be made of the contribution to the reported landings biomass, where 20% of the landings are supplied by overexploited and collapsed stocks. However, given the quality of the underlying catch statistics, this diagnosis is tentative, even though its severity is likely to apply.

Catch from bottom impacting gear:

The percentage of catch from the bottom gear type to the total catch reached its first peak at 23% in 1966 and then declined to less than 10% in the 1970s. In the recent decade, this percentage fluctuated around 20%.

Fishing effort:

The total effective effort continuously increased from around 10 million kW in the 1950s to its peak at 100 million kW in the late 1990s.

Primary Production Required:

The primary production required (PPR) to sustain the reported landings for the LME reached 7% of the observed primary production in the early 1970s, and has fluctuated between 5 to 6% in recent years. This is probably an underestimate due to the large under-reporting of catch in the region

Catch potential projections (under global warming):

Pollution and Ecosystem Health

Pollution

Nutrient ratio, Nitrogen load and Merged Indicator:

Human activities in watersheds are affecting nutrients transported by rivers into LMEs. Large amounts of nutrients (in particular nitrogen load) entering coastal waters of LMEs can result in high biomass algal blooms, leading to hypoxic or anoxic conditions, increased turbidity and changes in community composition, among other effects. In addition, changes in the ratio of nutrients entering LMEs can result in dominance by algal species that have deleterious effects (toxic, clog gills of shellfish, etc.) on ecosystems and humans. An overall nutrient indicator (Merged Nutrient Indicator) based on 2 sub-indicators: Nitrogen Load and Nutrient Ratio (ratio of dissolved Silica to Nitrogen or Phosphorus - the Index of Coastal Eutrophication Potential or ICEP) was calculated.

Nitrogen load:

The Nitrogen Load risk level for contemporary (2000) conditions was low (level 2 of the five risk categories, where 1 = lowest risk; 5 = highest risk). Based on a “current trends” scenario (Global Orchestration), this remained the same in 2030 and 2050.

Nutrient ratio:

The Nutrient Ratio (ICEP) risk level for contemporary (2000) conditions was moderate (3). According to the Global Orchestration scenario, this remained the same in 2030 and increased to high in 2050.

Merged nutrient indicator:

The risk level for the Merged Nutrient Indicator for contemporary (2000) conditions was low (2). According to the Global Orchestration scenario, this remained the same in 2030 and 2050.

POPs:

Only one sample is available for this LME from Morro de Sao Paulo. The location shows a concentration (ng.g^-1 of pellets) of 65 for PCBs, 777 for DDTs, and 4.7 for HCHs. These correspond to risk category 3 for PCBs, 5 for DDTs, and 2 for HCHs, of the five risk categories (1 = lowest risk; 5 = highest risk). The concentration of DDTs (777 ng.g^-1 of pellets) was the highest recorded among all the locations for which samples are available. Because of the subtropical climate, the application of DDT pesticide for Malaria control was suspected. More locations should be sampled and analyzed for proper evaluation of the LME.

Plastic debris:

Modelled estimates of floating plastic abundance (items km^-2), for both micro-plastic (<4.75 mm) and macro-plastic (>4.75 mm), indicate that this LME is in the group with relatively low levels of plastic concentration. Estimates are based on three proxy sources of litter: shipping density, coastal population density and the level of urbanisation within major watersheds, with enhanced run-off. The low values are due to the relative remoteness of this LME from significant sources of plastic. The abundance of floating plastic in this category is estimated to be on average over 40 times lower that those LMEs with the highest values. There is limited evidence from sea-based direct observations and towed nets to support this conclusion.

Ecosystem Health

Mangrove and coral cover:

0.14% of this LME is covered by mangroves (US Geological Survey, 2011) and 0.1% by coral reefs (Global Distribution of Coral Reefs, 2010).

Reefs at risk:

This LME has a present (2011) integrated threat index (combining threat from overfishing and destructive fishing, watershed-based and marine-based pollution and damage) of 208. 17% of coral reefs cover is under very high threat, and 21% under high threat (of the 5 possible threat categories, from low to critical). When combined with past thermal stress (between 1998 and 2007), these values increase to 29% and 18% for very high and high threat categories respectively. By year 2030, 28% of coral cover in this LME is predicted to be under very high to critical level of threat from warming and acidification; this proportion increases to 39% by 2050.

Marine Protected Area change:

The East Brazil Shelf LME experienced an increase in MPA coverage from 354 km² prior to 1983 to 16,399 km² by 2014. This represents an increase of 4,536%, within the medium category of MPA change.

Cumulative Human Impact:

The East Brazil Shelf LME experiences well above average overall cumulative human impact (score 4.13; maximum LME score 5.22), which is also well above the LME with the least cumulative impact. It falls in risk category 4 of the five risk categories (1 = lowest risk; 5 = highest risk). This LME is most vulnerable to climate change. Of the 19 individual stressors, three connected to climate change have the highest average impact on the LME: ocean acidification (1.04; maximum in other LMEs was 1.20), UV radiation (0.60; maximum in other LMEs was 0.76), and sea surface temperature (1.57; maximum in other LMEs was 2.16). Other key stressors include commercial shipping, sea level rise, ocean based pollution, pelagic high-bycatch commercial fishing, and demersal destructive commercial fishing.

Ocean Health Index:

The East Brazil Shelf LME scores below average on the Ocean Health Index compared to other LMEs (score 69 out of 100; range for other LMEs was 57 to 82). This score indicates that the LME is well below its optimal level of ocean health, although there are some aspects that are doing well. Its score in 2013 increased 2 points compared to the previous year, due in large part to changes in the scores for coastal livelihoods and clean waters. This LME scores lowest on food provision, natural products, tourism & recreation and iconic species goals and highest on artisanal fishing opportunities, carbon storage, coastal economies, lasting special places, and habitat biodiversity goals. It falls in risk category 4 of the five risk categories, which is a relatively high level of risk (1 = lowest risk; 5 = highest risk).

Socio-economics

Indicators of demographic trends, economic dependence on ecosystem services, human wellbeing and vulnerability to present-day extreme climate events and projected sea level rise, are assessed for the East Brazil Shelf LME. To compare and rank LMEs, they were classified into five categories of risk (from 1 to 5, corresponding to lowest, low, medium, high and highest risk, respectively) based on the values of the individual indicators. In the case of economic revenues, the LMEs were grouped to 5 classes of revenues from lowest, low, medium, high and highest, as revenues did not translate to risk.

Population:

The littoral area extends from Piaui in the north to Rio de Janeiro in the south and covers a total of 302,293 km². A current population of 34 million is projected to increase to 49 million in 2100, and density increasing from 113 persons per km² in 2010 to 162 per km² by 2100. About 38% of coastal population lives in rural areas, and is projected to increase in share to 40% in 2100.

Coastal poor:

The indigent population makes up 21% of the LME’s coastal dwellers. The East Brazil Shelf LME places in the high-risk category based on percentage and absolute number of coastal poor (present day estimate).

Revenues and Spatial Wealth Distribution:

Fishing and tourism depend on ecosystem services provided by LMEs. The East Brazil Shelf LME ranks in the low revenue category in fishing revenues based on yearly average total ex-vessel price of US 2013 $218 million for the period 2001-2010. Fish protein accounts for 5% of the total animal protein consumption of the coastal population. Its yearly average tourism revenue for 2004-2013 of US 2013 $25,957 million places it in the medium revenue category. On average, LME-based tourism income contributes 10% to the national GDPs of the LME coastal states. Spatial distribution of economic activity (e.g. spatial wealth distribution) measured by night-light and population distribution as coarse proxies can range from 0.0000 (totally equal distribution and lowest risk) to 1.0000 (concentrated in 1 place and most inequitable and highest risk). The Night Light Development Index (NLDI) thus indicates the level of spatial economic development, and that for the East Brazil Shelf LME falls in the category that is of medium economic development, thus with medium risk.

Human Development Index:

Using the Human Development Index (HDI) that integrates measures of health, education and income, the present-day East Brazil Shelf LME HDI belongs to the medium HDI and medium-risk category. Based on an HDI of 0.739, this LME has an HDI Gap of 0.261, the difference between present and highest possible HDI (1.000). The HDI Gap measures an overall vulnerability to external events such as disease or extreme climate related events, due to less than perfect health, education, and income levels, and is independent of the harshness of and exposure to specific external shocks.
HDI values are projected to the year 2100 in the contexts of shared socioeconomic development pathways (SSPs). The East Brazil Shelf LME is projected to assume a place in the very low risk category (very high HDI) in 2100 under a sustainable development pathway or scenario. Under a fragmented world scenario, this LME is estimated to place in the very high-risk category (very low HDI) because of reduced income level and increased population size compared to estimated income and population values in a sustainable development pathway.

Climate-Related Threat Indices:

The Climate-Related Threat Indices utilize the HDI Gaps for present-day and projected 2100 scenarios. The contemporary climate index accounts for deaths and property losses due to storms, flooding and extreme temperatures incurred by coastal states during a 20-year period from 1994 to 2013 as hazard measures, the 2010 coastal population as proxy for exposure, and the present day HDI Gap as vulnerability measure.
The Contemporary Threat Index incorporates a Dependence Factor based on the fish protein contribution to dietary animal protein, and on the mean contribution of LME tourism to the national GDPs of LME coastal states. The HDI Gap and the degree of dependence on LME ecosystem services define the vulnerability of a coastal population. It also includes the average of risk related to extreme climate events, and the risk based on the degrading system states of an LME (e.g. overexploited fisheries, pollution levels, decrease in coastal ecosystem areas).
The 2100 sea level rise threat indices, each computed for the sustainable world and fragmented world development pathways, use the maximum projected sea level rise at the highest level of warming of 8.5 W/m² in 2100 as hazard measure, development pathway-specific 2100 populations in the 10 m × 10 km coast as exposure metrics, and development pathway-specific 2100 HDI Gaps as vulnerability estimates.
Present day climate threat index to the East Brazil Shelf LME is within the high-risk (high threat) category. The combined contemporaneous risk due to extreme climate events, degrading LME states and the level of vulnerability of the coastal population, is medium. In a sustainable development scenario, the risk index from sea level rise in 2100 is very low, and increases to high risk under a fragmented world development pathway.