Benguela Current
Click here to choose an LME

×
← go back to the LME Portal

LME 29: Benguela Current

Bordering countries:

Angola, Namibia, South Africa

LME total area:

1,470,134 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 very high.

Productivity

Chlorophyll-A:

The annual Chlorophyll a concentration (CHL) cycle has a maximum peak (0.835 mg.m^-3) in September and a minimum (0.434 mg.m^-3) during January. The average CHL is 0.550 mg.m^-3. Maximum primary productivity (410 g.C.m^-2.y^-1) occurred during 1999 and minimum primary productivity (352 g.C.m^-2.y^-1) during 2013. There is a statistically insignificant decreasing trend in Chlorophyll of -6.25 % from 2003 through 2013. The average primary productivity is 377 g.C.m^-2.y^-1, which places this LME in Group 4 of 5 categories (with 1 = lowest and 5= highest).

Primary productivity:

Sea Surface Temperature:

From 1957 to 2012, the Benguela Current LME #29 has warmed by 0.27°C, thus belonging to Category 4 (slow warming LME). The Benguela Current’s thermal history was punctuated by events associated with Benguela El Niños and La Niñas. Fidel and O’Toole (2007) distinguished five major Benguela El Niños over the last 50 years. The most pronounced warming of >1.2°C occurred after the all-time minimum of 1958 and took 5 years to peak in 1963. Other warm events peaked in 1973 and 1984, alternated with cold events of 1982 and 1992. Clearly, decadal variability in the Benguela Current was strong through the last warm event of 1984. After that, the Benguela Current experienced a shift to a new, warm regime, in which decadal variability is subdued. The thermal history of this LME bears almost no resemblance to either that of the Guinea Current LME #28 (its northern neighbor) or that of the Agulhas Current LME #30 (its southern neighbor).

Fish and Fisheries

The Benguela Current LME is very rich in pelagic and demersal fish. Most of the LME’s major fisheries resources are shared between the bordering countries or migrate across national jurisdictional zones, and include sardine (Sardinops sagax), anchovy (Engraulis capensis), hake (Merluccius capensis and M. paradoxus), horse mackerel (Trachurus and T. trecae), sardinella (Sardinella spp.), and rock lobster (Jasus lalandii). Artisanal, commercial (industrial) and recreational fisheries are all of significance in the LME, with artisanal fisheries being particularly important for Angola.

Annual catch:

Total reported landings of the LME increased steadily from 1950 to a peak of about 2.8 million t in 1978. In the subsequent years, however, the landings show a general decline, down to about 1.1 million t in the 2000s.

Catch value:

The trend in the value of the reported landings closely resembles that of the reported landings, peaking at just under 2.4 billion US$ (in 2005 real US$) in 1969.

Marine Trophic Index and Fishing-in-Balance index:

Since the mid-1970s, the mean MTI has been relatively stable in this LME, but as the amount of catch (tonnage) has declined over the same period, the FiB index shows a rapid decline. This decline of the FiB index is particularly strong off Namibia, which is a case of ‘fishing down marine food webs’ but one in which the species that replaced the exploited species are presently not targeted by fisheries.

Stock status:

The Stock-Catch Status Plots indicate that about 35% of commercially exploited stocks in the LME has collapsed with another 25% overexploited stocks contributing 50% of the catch. However, fully exploited stocks, while accounting for less than 20% of the stocks, provide less than 20% of the reported landings.

Catch from bottom impacting gear:

The percentage of catch from the bottom gear type to the total catch increased from 3% in the 1950s to its first peak at around 10% in 1971. In the recent decade, this percentage kept increasing and reached its maximum at 12% in 2008.

Fishing effort:

The total effective effort continuously increased from around 2 million kW in the 1950s to its peak at 83 million kW in 1990. The fishing effort then fluctuated between 10 and 80 million kW in the recent two decades.

Primary Production Required:

The primary production required (PPR) to sustain the reported landings in the LME reached one third of the observed primary production by the mid-1970s, but has since declined to half that level.

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 low. (level 1 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 increased to low in 2050.

Nutrient ratio:

The Nutrient Ratio (ICEP) risk level for contemporary (2000) conditions was high (4). 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 low (1). According to the Global Orchestration scenario, this remained the same in 2030 and increased to low in 2050.

POPs:

Data are available for one sample from one location near Yzerfontein. This location shows moderate concentration (ng.g^-1 of pellets) of PCBs (61) and DDTs (24), and low concentration of HCHs (3.0). PCBs and DDTs concentrations at this location correspond to risk category 3, while HCHs to category 2 of the five risk categories (1 = lowest risk; 5 = highest risk). At this location, Ryan et al. (2012) studied temporal trends by using time-series pellet samples and a showed drastic decrease in DDTs and HCHs concentrations from 1980s to 2008. However, PCBs showed an increase from 1999 to 2008, suggesting current inputs. Continuous monitoring is recommended.

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 very limited evidence from sea-based direct observations and towed nets to support this conclusion.

Ecosystem Health

Mangrove and coral cover:

0.03% of this LME is covered by mangroves (US Geological Survey, 2011).

Reefs at risk:

Not applicable.

Marine Protected Area change:

The Benguela Current LME experienced an increase in MPA coverage from 92 km² prior to 1983 to 20,855 km² by 2014. This represents an increase of 22,668%, within the high category of MPA change.

Cumulative Human Impact:

The Benguela Current LME experiences an above average overall cumulative human impact (score 3.70; maximum LME score 5.22), which is also 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, three connected to climate change have the highest average impact on the LME: ocean acidification (1.05; maximum in other LMEs was 1.20), UV radiation (0.64; maximum in other LMEs was 0.76), and sea surface temperature (1.54; maximum in other LMEs was 2.16). Other key stressors include commercial shipping, ocean based pollution, and demersal non-destructive low-bycatch commercial fishing.

Ocean Health Index:

The Benguela Current LME scores the lowest of any LME on the Ocean Health Index (score 57 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 increase 2 points compared to the previous year, due in large part to changes in the score for coastal economies. This LME scores lowest on food provision, natural products, coastal protection, tourism & recreation, and iconic species goals and highest on the artisanal fishing opportunities goal. It falls in risk category 5 of the five risk categories, which is the highest 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 this 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 coastal area stretches over 364 147 km². A current population of 9 720 thousand in 2010 is projected to increase to 24 515 thousand in 2100, with a density of 27 persons per km² in 2010 increasing to 67 per km² by 2100. About 16% of coastal population lives in rural areas, and is projected to increase in share to 49% in 2100.

Coastal poor:

The indigent population makes up 29% of the LME’s coastal dwellers. This LME places in the very 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. This LME ranks in the high-revenue category in fishing revenues based on yearly average total ex-vessel price of US 2013 $1 202 million for the period 2001-2010. Fish protein accounts for 16% of the total animal protein consumption of the coastal population. Its yearly average tourism revenue for 2004-2013 of US 2013 $6 131 million places it in the low-revenue category. On average, LME-based tourism income contributes 8% 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 this LME falls in the category with very high risk.

Human Development Index:

Using the Human Development Index (HDI) that integrates measures of health, education and income, the present-day LME HDI belongs to the very low HDI and very high-risk category. Based on an HDI of 0.576, this LME has an HDI Gap of 0.424, 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). This LME is projected to assume a place in the low risk category (high HDI) in 2100 under a sustainable development pathway. Under a fragmented world scenario, the LME is estimated to place in a very high-risk category (very low HDI) because of reduced income levels and increased population values from those estimated in a sustainable development scenario.

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 of this 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 high. In a sustainable development scenario, the risk index from sea level rise in 2100 is medium, and increases to very high risk under a fragmented world development pathway.

Governance

Governance architecture:

In this LME the Benguela Current Commission provides for full integration across issues in the EEZs that it covers. It is the integration between the highly migratory species arrangement (ICCAT) and the area beyond national jurisdiction arrangement (SEAFO) and between those arrangements and the Benguela Current Comission (BCC) that are unclear. In the broader assessment, the presence of the BCC arrangement that is clearly designed to integrate issues for the LME is overriding and a score of 1 is assigned for integration due to the presence of this arrangement.
The overall scores for ranking of risk were: