Oyashio Current
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LME 51: Oyashio Current

Bordering countries:

Japan, Russian Federation

LME total area:

663,609 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 low.

Productivity

Chlorophyll-A:

The annual Chlorophyll a concentration (CHL) cycle has a maximum peak (0.871 mg.m^-3) in May and a minimum (0.255 mg.m^-3) during February. The average CHL is 0.493 mg.m^-3. Maximum primary productivity (263 g.C.m^-2.y^-1) occurred during 1998 and minimum primary productivity (167 g.C.m^-2.y^-1) during 2009. There is a statistically significant decreasing trend in Chlorophyll of -8.07 % from 2003 through 2013. The average primary productivity is 192 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:

From 1957 to 2012, the Oyashio Current LME #51 has warmed by 0.68°C, thus belonging to Category 3 (moderate warming LME). The thermal history of this LME is somewhat similar to those of the East China Sea and Kuroshio Current. It consists of two regimes, cold and warm. The cold regime lasted through 1985-1987. The abrupt SST increase in the late 1980s resulted in the all-time maximum of almost 7.5°C in 1990, a 1.3°C increase in just 5 years. The well-documented trans-Pacific regime shift in 1976-1977 (Hare and Mantua, 2000) was not apparent in the Oyashio Current LME, even though the SST reached its absolute minimum in 1976. On the opposite, the next trans-Pacific regime shift, of 1988-1989 (Hare and Mantua, 2000), was pronounced, even dramatic, in the Oyashio Current LME. The long-term warming along the Oyashio Current and associated Polar Front was pronounced in winter, when SST rose at a rate of 1°C/decade, whereas in summer the long-term warming was negligible (Belkin et al., 2002).

Fish and Fisheries

The Oyashio Current off the Pacific coast of the Kuril Islands is among the world’s most productive marine areas and Russia’s largest fishing ground.

Annual catch:

Total reported landings in the LME exceeded 1 million t in the 1989, with large catch of Alaska pollock and Pacific sardine, but recorded around 600,000 t in the recent decade.

Catch value:

The reported value of the landings had a peak of 1 billion US$ (in 2005 real US$) recorded in 1979.

Marine Trophic Index and Fishing-in-Balance index:

The MTI shows large fluctuations, reflecting the cyclic nature in the relative abundance, and hence the landings, of Pacific sardine. The FiB index shows a period of expansion in the 1950s and 1970s. Then, the FiB index declines from mid 1970s to early 1980s, after which the index levels off until late 1990s, indicating that the decrease in the mean trophic level resulting from the high proportion of Pacific sardine in the reported landings in the 1980s was compensated for by its large landings.

Stock status:

The Stock-Catch Status Plots indicate that the number of fully exploited stocks have been rapidly increasing, accounting for 50% of the commercially exploited stocks in the few recent years, with an additional 25% of the stocks being either collapsed or overexploited. Overexploited stocks contributed 30% of the catch biomass in 2010.

Catch from bottom impacting gear:

The percentage of catch from the bottom gear type to the total catch decreased from around 7% in the 1950s to its lowest point at around 2% in 1987. Then, this percentage kept increasing and reached its peak at 19% in 2001. The percentage fluctuated around 12% in recent decade.

Fishing effort:

The total effective effort continuously increased from around 2 million kW in the 1950s to its peak around 12.5 million kW in 2005.

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-1980s and in 1995, but has not reached such level since. With Russia selling the rights to fish inside its EEZ, a large number of foreign fleets, mainly those from China and South Korea, as well as a number of flag of convenience vessels operate within the LME

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 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 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 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:

Not applicable

Reefs at risk:

Not applicable

Marine Protected Area change:

The Oyashio Current LME experienced an increase in MPA coverage from 466 km² prior to 1983 to 556 km² by 2014. This represents an increase of 19%, within the lowest category of MPA change.

Cumulative Human Impact:

The Oyashio Current LME experiences below average overall cumulative human impact (score 3.21; 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 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 (0.78; maximum in other LMEs was 1.20), UV radiation (0.76; maximum in other LMEs was 0.76), and sea surface temperature (0.91; maximum in other LMEs was 2.16). Other key stressors include commercial shipping, ocean based pollution, and all three types of demersal commercial fishing (demersal destructive, non-destructive low-bycatch, and non-destructive high-bycatch).

Ocean Health Index:

The Oyashio Current LME scores below average on the Ocean Health Index compared to other LMEs (score 68 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 decreased 1 point compared to the previous year, due in large part to changes in the score for clean waters. This LME scores lowest on food provision, natural products, and tourism & recreation goals and highest on artisanal fishing opportunities, coastal protection, carbon storage, ecoastal 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 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 37 156 km². A current population of 999 thousand in 2010 is projected to decrease to 412 thousand in 2100, with a density of 27 persons per km² in 2010 decreasing to 11 per km² by 2100. About 62% of coastal population lives in rural areas, and is projected to maintain this share in 2100.

Coastal poor:

The indigent population makes up 16% of the LME’s coastal dwellers. This LME places in the high-risk category based on percentage and in the low-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 $952 million for the period 2001-2010. Fish protein accounts for 37% of the total animal protein consumption of the coastal population. Its yearly average tourism revenue for 2004-2013 of US 2013 $14 149 million places it in the low-revenue category. On average, LME-based tourism income contributes 7% 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 low 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 high HDI and very low-risk category. Based on an HDI of 0.883, this LME has an HDI Gap of 0.117, 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 very low risk category (very high HDI) in 2100 under a sustainable development pathway. Under a fragmented world scenario, the LME is estimated to place in a medium-risk category (medium HDI) because of reduced income levels and population values from those 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 of this LME is within the medium-risk (medium 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 remains very low under a fragmented world development pathway.

Governance

Governance architecture:

In this LME, there is essentially no transboundary fisheries arrangement. However, PICES does provide opportunity for transboundary cooperation in assessment and science. Also, the fact that there is no Regional Seas convention covering the area, but only an action plan (NOWPAP), seriously weakens capacity for transboundary governance in areas relating to pollution. Further, there is no indication of transboundary integration between the fisheries and pollution issues, other than through cooperation in science. There is the potential for integration of pollution and biodiversity issues under NOWPAP should it proceed to the level of a Convention. There does not appear to be any other organisation than NOWPAP that could integrate and coordinate across the full range of issues required for EBM.
The overall scores for ranking of risk were: