East Bering Sea
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LME 1: East Bering Sea

Bordering country:

United States of America

LME total area:

1,193,601 km²

LME overall risk:

This LME falls in the cluster of LMEs that exhibit medium numbers of collapsed and overexploited fish stocks, as well as very 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 medium.

Productivity

Chlorophyll-A:

The annual Chlorophyll a concentration (CHL) cycle has a maximum peak (1.12 mg.m^-3) in May and a minimum (0.309 mg.m^-3) during November. The average CHL is 0.692 mg.m^-3. Maximum primary productivity (291 g.C.m^-2.y^-1) occurred during 1999 and minimum primary productivity (175 g.C.m^-2.y^-1) during 2007. There is a statistically insignificant decreasing trend in Chlorophyll of -19.1 % from 2003 through 2013. The average primary productivity is 235 g.C.m^-2.y^-1, which places this LME in Group 3 of 5 categories (with 1 = lowest and 5= highest).

Primary productivity:

Sea Surface Temperature:

Between 1957 and 2012, the East Bering Sea LME #1 has warmed by 0.24°C. It thus belongs to Category 4 (slow-warming LME). The 1957-2012 time span included periods with opposite SST trends. From 1957 through 1971 SST decreased by >1°C. The SST drop was especially abrupt in the late 1960s-early 1970s. The cold spell lasted through 1976, after which SST jumped by ~1°C in one year and remained relatively high through 2003. The 1°C SST jump from 4°C to 5°C between 1976 and 1977 was a manifestation of a “regime shift” in the North Pacific that occurred during the winter of 1976-1977, caused by a large-scale shift of the North Pacific atmospheric pressure pattern (Hare and Mantua, 2000). After peaking at 5.5°C in 1998 and at 5.4°C in 2003, SST plunged below 4.2°C by 2012, a drop of 1.2°C in 9 years.

Fish and Fisheries

The East Bering Sea LME supports the world’s largest single-species fishery, targeting Alaska pollock (Theragra chalcogramma).

Annual catch:

Reported landings of this fishery now range between 0.4 and 0.7 million t, a level thought to be sustainable. Other commercially valuable species include halibut, herring, capelin, Pacific cod, skate, flounder, Greenland turbot, sole, dab, plaice and crab. Total reported landings rose steadily to a historic high of 1.8 million t in 1986, followed by a decline to 1.1million t in the mid-2000s and then followed by a further decline to 0.9 million t in the recent years.

Catch value:

The value of the fishery reached its peak at 1.9 billion US$ (in 2005 US$) in 1979.

Marine Trophic Index and Fishing-in-Balance index:

The MTI declined from the 1950s to the early 1970s, but has since leveled off at around 3.5 due to the enormous catch of Alaska pollock. The geographic expansion which led to this dominance of Alaska pollock is suggested by the increase of the FiB index from the mid-1970s to the mid-1980s. The system appears sustainable according to these two indices, although it must be stressed that such an interpretation is based on the overwhelming effect of a single, well-managed species.

Stock status:

The Stock-Catch Status Plots indicate that about 40% of the commercially exploited stocks have collapsed. The majority of the reported landings is still supplied by overexploited stocks, or more specifically, by Alaska pollock.

Catch from bottom impacting gear:

The percentage of catch from the bottom gear type to the total catch reaches its maximum at 19% in 1965 and then this percentage ranges between 6 to 13% in the recent few decades.

Fishing effort:

The total effective effort fluctuated around 20 million kW from 1950 to 1980 and started to increase since the 1980s. It keeps increasing continuously in the last few decades and reaches its maximum in 2005 at 56 million kW.

Primary Production Required:

The primary production required (PPR) to sustain the reported landings in this LME reached 25% of the observed primary production in the mid of the 1980s, and has dropped to less than 15% in recent years.

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 2050.

Nutrient ratio:

The Nutrient Ratio (ICEP) risk level for contemporary (2000) conditions was low (2). 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 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 the lowest 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 remoteness of this LME from significant sources of plastic. The abundance of floating plastic in this category is estimated to be over 400 times lower than 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:

Not applicable

Reefs at risk:

Not applicable

Marine Protected Area change:

The East Bering Sea LME experienced an increase in MPA coverage from 13,228 km² prior to 1983 to 122,905 km² by 2014. This represents an increase of 829%, within the low category of MPA change.

Cumulative Human Impact:

The East Bering Sea LME experiences an average overall cumulative human impact (score 3.1; maximum LME score 5.22), but which is still well above the LME with the least cumulative impact. It falls in risk category 2 of the five risk categories (1 = lowest risk; 5 = highest risk). This LME is particularly vulnerable to climate change. Of the 19 individual stressors, three connected to climate change have the highest average impact on the LME: sea surface temperature (1.13; maximum in other LMEs was 2.16), UV radiation (0.73; maximum in other LMEs was 0.76), and ocean acidification (0.58; maximum in other LMEs was 1.20). Other key stressors include commercial shipping, ocean based pollution, and demersal destructive commercial fishing.

Ocean Health Index:

The East Bering Sea LME scores above average on the Ocean Health Index compared to other LMEs (score 72 out of 100; range for other LMEs was 57 to 82) but still relatively low. This score indicates that the LME is well below its optimal level of ocean health, although there are many aspects that are doing well. Its score in 2013 increased by 9 points compared to the previous year, due in large part to changes in the scores for clean waters and natural products goals. This LME scores lowest on mariculture, tourism & recreation and natural products goals, and highest on artisanal fishing opportunities, coastal protection, coastal economies, lasting special places, and species diversity goals. It falls in risk category 2 of the five risk categories, which is a moderate 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 Bering Sea 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 coast includes the southwest fringe of the Alaskan Peninsula and is among the most sparsely populated (lowest risk) and completely rural of LMEs. It covers 140,753 km², with a density of 1 person every 4 km² in 2010 and decreasing to 1 person every 5 km² in 2100.

Coastal poor:

The indigent population makes up 17% of the LME’s coastal dwellers. This LME places in the high-risk category based on percentage of poor but among those with the lowest absolute number of poor at 5700 (present day estimate).

Revenues and Spatial Wealth Distribution:

Fishing and tourism depend on ecosystem services provided by LMEs. The East Bering Sea LME ranks in the high revenue category in fishing revenues based on yearly average total ex-vessel price of US 2013 $1.15 billion (thousand million) for the period 2001-2010. Fish protein accounts for 7% of the total animal protein consumption of the coastal population. Its yearly average tourism revenue for 2004-2013 of US 2013 $4.2 billion 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 the East Bering Sea LME falls in the category with lowest risk.

Human Development Index:

Using the Human Development Index (HDI) that integrates measures of health, education and income, the present-day East Bering Sea LME HDI belongs to the highest HDI and lowest risk category. Based on an HDI of 0.909, this LME has an HDI Gap of 0.091, 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 Bering Sea LME is projected to maintain its position in the lowest risk category (highest HDI) in 2100 under a sustainable development pathway or scenario. Under a fragmented world scenario, this LME is projected to slip to the high risk category (low HDI) because of reduced income level and bigger 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 to the East Bering Sea LME is within the low risk (low 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 low. Regardless of development pathway, this LME is projected to belong to the lowest risk category that is least threatened by sea level rise in 2100.

Governance

Governance architecture:

The four fisheries arrangements in this LME - NPAFC, CCBSP, IPHC and WCPFC - are unique in addressing specific types of fisheries. The only area for commonality appears to be in the form of scientific advice being provided with input from PICES in arrangements relating to halibut, pollock and anadromous species. Additionally, the member countries are primarily responsible for implementation across all of the arrangements. The Arctic Council provides for some level of integration across pollution (LBS and MBS) and for biodiversity (general) in the part of the LME that is covered by the Arctic Council. However, overall, no integrating mechanisms, such as an overall policy coordinating organisation 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 ranking of risk were: