North Brazil Shelf
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LME 17: North Brazil Shelf

Bordering countries:

Brazil, France(French Guiana), Guyana, Suriname, Venezuela

LME total area:

1,034,575 km²

LME overall risk:

This LME falls in the cluster of LMEs that exhibit high percentages of rural coastal population, high numbers of collapsed and overexploited fish stocks, as well as high proportions of catch from bottom impacting gear.
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 (0.598 mg.m^-3) in June and a minimum (0.251 mg.m^-3) during November. The average CHL is 0.373 mg.m^-3. Maximum primary productivity (686 g.C.m^-2.y^-1) occurred during 2010 and minimum primary productivity (587 g.C.m^-2.y^-1) during 2012. There is a statistically insignificant increasing trend in Chlorophyll of 1.74 % from 2003 through 2013. The average primary productivity is 623 g.C.m^-2.y^-1, which places this LME in Group 5 of 5 categories (with 1 = lowest and 5= highest).

Primary productivity:

Sea Surface Temperature:

From 1957 to 2012, the North Brazil Shelf LME #17 has warmed by 0.38°C, thus belonging to Category 4 (slow warming LME). The cooling regime of 1957-1976 resulted in the all-time minimum of 27.3°C in 1976, after which a long-term warming peaked at 28.6°C in 2010. The long-term SST increase between 1957 and 2012 amounted to 0.38°C. The SST warming rate between the absolute minimum of 27.3°C in 1976 and the absolute maximum of 28.6°C in 2010 was 1.3°C in 34 years. The well-defined regime shift of 1976 (from cooling to warming) in the North Brazil Shelf LME was decoupled from events in the South Brazil Shelf LME, which can be explained by the divergent pattern of ocean circulation, with currents flowing in opposite directions, due south in the South Brazil Shelf LME and due north in the North Brazil Shelf LME. Among major events, the warm event of 2010 in the North Brazil Shelf LME had no counterpart in the South Brazil Shelf LME, where the SST peaked in 2001 and declined afterward.

Fish and Fisheries

The multispecies and multigear fisheries of the North Brazil Shelf LME are targeted by both national and foreign fleets. Major exploited groups include a variety of groundfish such as weakfish (Cynoscion sp.), whitemouth croaker or corvina (Micropogonias furnieri) and sea catfish (Arius sp.). The shrimp resources, such as southern brown shrimp (Penaeus subtilis), pink spotted shrimp (P. brasiliensis), southern pink shrimp (P. notialis), southern white shrimp (P. schmitti) as well as the smaller seabob (Xiphopenaeus kroyeri) support one of the most important shrimp fisheries in the world. Tuna is also exploited.

Annual catch:

Total reported landings in this LME increased steadily from 38,000 t in 1950 to 320,000 t in 2006.

Catch value:

The value of the reported landings reached 650 million US$ (in 2005 real US$) in 1973.

Marine Trophic Index and Fishing-in-Balance index:

From the mid-1980s, the MTI has undergone a steady decline, a trend indicative of a ‘fishing down’ of the food webs in the LME, while the flatness of the FiB over the same period implies that the increase in the reported landings have not compensated for the decline in the mean trophic level.

Stock status:

The Stock-Catch Status Plots indicate that over 50% of commercially exploited stocks in the LME are either overexploited or have collapsed. However, about 70% of the reported landings come from fully exploited stocks.

Catch from bottom impacting gear:

The percentage of catch from the bottom gear type to the total catch ranged between 28 and 48% in these 60 years.

Fishing effort:

The total effective effort continuously increased from around 10 million kW in the 1950s to its peak at 80 million kW in the mid-2000s.

Primary Production Required:

The primary production required (PPR) to sustain the reported landings in this LME is low, currently at 3% of the observed primary production.

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 very high. (level 5 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 very low (1). According to the Global Orchestration scenario, this remained the same in 2030 and 2050.

Merged nutrient indicator:

The risk level for the Merged Nutrient Indicator for contemporary (2000) conditions was very high (5). According to the Global Orchestration scenario, this remained the same in 2030 and 2050.

POPs:

No pellet samples were obtained from this 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:

The North Brazil Shelf has the highest mangrove coverage of any LME, at 10429 km². This amounts to 0.98% the total area (US Geological Survey, 2011). 0.01% of this LME is covered by coral (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 103. This is the lowest integrated threat score of any LME. 92% of coral reefs cover is under low threat (of the 5 possible threat categories, from low to critical). When combined with past thermal stress (between 1998 and 2007), 97% of coral reef cover is rated at medium threat and 3% at high threat. These threat levels are not predicted to change by the year 2030 and 2050.

Marine Protected Area change:

The North Brazil Shelf LME experienced an increase in MPA coverage from 3,312 km² prior to 1983 to 40,957 km² by 2014. This represents an increase of 11.4%, within the low category of MPA change.

Cumulative Human Impact:

The North Brazil Shelf LME experiences an above average overall cumulative human impact (score 3.81; maximum LME score 5.22), which is well above the LME with the least cumulative impact. It falls in risk category 3 of the five risk categories (1 = lowest risk; 5 = highest risk). This LME is most vulnerable to climate change. Of the 19 individual stressors, all four connected to climate change have the highest average impact on the LME: sea surface temperature (1.61; maximum in other LMEs was 2.16), ocean acidification (0.84; maximum in other LMEs was 1.20), UV radiation (0.53; maximum in other LMEs was 0.76), and sea level rise (0.30; maximum in other LMEs was 0.71). Other key stressors include commercial shipping, ocean based pollution, and demersal destructive commercial fishing.

Ocean Health Index:

The North Brazil Shelf LME scores below average on the Ocean Health Index compared to other LMEs (score 67 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 & economies 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, 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 North 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 eastern part of Venezuela in the west to the Brazilian State of Maranhāo in the east and covers a total of 508,610 km². A current population of 9.6 million is projected to slightly increase to 10.9 million in 2100, and density increasing from 19 persons per km² in 2010 to 21 per km² by 2100. About 47% of coastal population lives in rural areas, and is projected to increase in share to 55% in 2100.

Coastal poor:

The indigent population makes up 22% of the LME’s coastal dwellers. The North Brazil Shelf LME places in the high-risk category based on percentage and in the medium risk category using absolute number of coastal poor (present day estimate).

Revenues and Spatial Wealth Distribution:

Fishing and tourism depend on ecosystem services provided by LMEs. The North Brazil Shelf LME ranks in the medium revenue category in fishing revenues based on yearly average total ex-vessel price of US 2013 $561 million for the period 2001-2010. Fish protein accounts for 9% of the total animal protein consumption of the coastal population. Its yearly average tourism revenue for 2004-2013 of US 2013 $6,541 million places it in the low revenue category. On average, LME-based tourism income contributes 9% 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 North Brazil Shelf LME falls in the category that is of lowest economic development, thus with very high risk.

Human Development Index:

Using the Human Development Index (HDI) that integrates measures of health, education and income, the present-day North Brazil Shelf LME HDI belongs to the medium HDI and medium-risk category. Based on an HDI of 0.731, this LME has an HDI Gap of 0.269, 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 North 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 North 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 very high. 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.

Governance

Governance architecture:

The two transboundary arrangements for fisheries (CRFM and WECAFC) in the areas within national jurisdiction are closely connected. So are the two arrangements for pollution and biodiversity that fall under the Cartagena Convention. However neither of these pairs appears to be integrated with each other or with the tuna arrangement (ICCAT) No integrating mechanisms, such as an overall policy coordinating organization for the LME, could be found. There may be interaction amongst the arrangements through participation in each other’s meetings, but this appears to be informal.
The overall scores for the ranking of risk were: