Western Pacific Warm Pool

Productivity

Chlorophyll-A:

The annual Chlorophyll a concentration (CHL) cycle has a maximum peak (0.0799 mg.m^-3) in March and a minimum (0.0590 mg.m^-3) during November. The average CHL is 0.0679 mg.m^-3. Maximum primary productivity (151 g.C.m^-2.y^-1) occurred during 1998 and minimum primary productivity (120 g.C.m^-2.y^-1) during 2002. There is a statistically insignificant increasing trend in Chlorophyll of 7.66 % from 2003 through 2013. The average primary productivity is 132 g.C.m^-2.y^-1, which places the Western Pacific Warm Pool in Group 1 of 5 categories (with 1 = lowest and 5= highest).

Primary productivity:

Sea Surface Temperature:

From 1957 to 2012, the West Pacific Warm Pool Province has warmed by 0.48°C, thus belonging to Category 3 (moderate warming region). The thermal history of this vast region consisted of two epochs separated by a regime change with a breakpoint in 1975. A cooling epoch can be identified from 1957 through 1975, during which SST decreased by 0.5°C, after which SST warmed sharply in 1976-1977. This abrupt warming could be tentatively linked to the North Pacific regime shift of 1976-1977 (Hare and Mantua, 2000), although the onset of warming occurred in this province about one year before it occurred elsewhere. Two warm events can be identified, in 1995 and 2003. The El Niño 1997-1998 did not manifest in this province. In many LMEs the El Niño 1997-1998 manifested as a warm peak of extreme magnitude. Thus, this province belongs to a very small subset of Pacific regions, where the El Niño 1997-1998 did not manifest the same way as elsewhere.

Fish and Fisheries

The Western Pacific Warm Pool (WPWP), which is not a designated LME, covers 13 million km² in the Central Western Pacific.

Annual catch:

As the WPWP is in effect, a vast expanse of deep tropical waters studded with small volcanic islands or atolls, the bulk of the fisheries catches consists of tunas and other large pelagic fishes caught in open waters (more than 50%), and smaller reef-associated fishes and invertebrates. In absolute terms, this amounted to an average of 130,000 t per year in the 1950s and 1960s, to between 1.0 – 1.4 million t since 1990. The catch of the WPWP from bottom-impacting gear went from a few hundred tonnes in 1950 to about 40,000 tonnes in 2010, which is currently about 4 % of the total catch, but as much as 20% of the non-tuna catch.

Marine Trophic Index and Fishing-in-Balance index:

The primary production required (PPR) to sustain the reported landings in the WPWP grew slowly from less that 1% in the early 1950 to about 2% in 1970, but it increased rapidly to a plateau of about 20 % in the mid-1990s, around which it now oscillates. Related to this, the MTI decreased from 1950 to the early 1970s, but picked up and plateaued from 1990 on as tuna and other high-trophic level pelagic fishes increased, the post-2006 increase being an artefact of the time series extension. The trend in the FiB index confirms this, and illustrates how the pelagic fisheries expanded their areas of operations.

Stock status:

The Stock-Catch Status Plots indicate that about 90 % of the catch of commercially exploited stocks in the WPWP are fully exploited, while stocks in the developing stage, estimated to be nearly 100% in the 1970s, has shrunk to 10%.

Catch from bottom impacting gear:

The percentage of catch from the bottom gear type to the total catch fluctuated between 1 and 6% from 1950 to 2010. This percentage fluctuated around 3% in the recent decade.

Fishing effort:

The total effective effort continuously increased from around 8 million kW in the 1950s to its peak around 2.4 billion kW in 2006.

Primary Production Required:

Pollution and Ecosystem Health

Ecosystem Health

Mangrove and coral cover:

0.003% of the Western Pacific Warm Pool is covered by mangroves (US Geological Survey, 2011) and 0.15 by coral reef (Global Distribution of Coral Reefs, 2010).

Reefs at risk:

The Western Pacific Warm Pool (WPWP) has a present (2011) integrated threat index (combining threat from overfishing and destructive fishing, watershed-based and marine-based pollution and damage) of 142. 1.44% of coral reefs cover is under very high threat, and 10% 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 6.55% and 19.85% for very high and high threat categories, respectively. By year 2030, 11.44% of coral cover in the WPWP is predicted to be under very high to critical level of threat from warming and acidification; this proportion remains unchanged in 2050.

Marine Protected Area change:

The Western Pacific Warm Pool experienced an increase in MPA coverage from 3,367 km² prior to 1983 to 114,485 km² by 2014. This represents an increase of 3,300%, within the medium category of MPA change

Cumulative Human Impact:

Socio-economics

The Pacific Warm Pool is a thermally dynamic region of the Western Pacific defined by the annual average sea surface temperature isotherm 28 °C and above. Within this shifting region are 14 oceanic island states that receive support from the Global Environment Facility: the Cook Islands, Federated States of Micronesia, Fiji, Kiribati, Marshall Islands, Nauru, Niue, Palau, Papua New Guinea, Samoa, Solomon Islands, Tonga-Tokelau, Tuvalu and Vanuatu (Honey and Sherman 2013). Though not an LME, the Pacific Warm Pool states are included in this study because they are inhabited coastal areas. Because of the limited data available for island states in general, only five island states (Fiji, Samoa, Solomon Islands, Tonga and Vanuatu) are assessed. The normalization process allows for comparisons among these five.

Population:

The populations of the five island states together account for 85% of the aggregate estimate for the 14 GEF beneficiary states in 2010. Close to 90% of the population are rural, and with relatively high rates of poverty, regionally referred as hardship.


Island state	Population (2010)
Fiji	854 098
Samoa	183 081
Solomon Islands	535 699
Tonga	104 260
Vanuatu	245 786

Human Development Index:

National poverty headcount ratios are highest for Vanuatu at 40%; Fiji, at 31%; 23% Solomons; and 20% in the case of Samoa (http://www.ruralpovertyportal.org /region/home/tags/oceania). As a result, the range of HDI values among these five island countries cuts across the three lower HDI classification groups with Fiji at the top having an average ranked 2013 HDI score (0.724) and Solomon Islands at the lowest (0.491) (Table 9).


Island state	HDI (2013)
Fiji	0.724
Samoa	0.694
Solomon Islands	0.491
Tonga	0.705
Vanuatu	0.616

Climate-Related Threat Indices:

The Present Day Climate Threat Index is highest for Solomon Islands because of its low HDI (high HDI Gap). However, Fiji comes second because it has the highest cyclone-related annual mortality rate and annual property losses incurred during the period 1994-2013. The differences in Sea Level Rise Threat Indices are influenced by the differences in projected HDI scores since sea level rise and population estimates are the same for both SSP1 and SSP3. Solomon Islands are the most vulnerable of the five oceanic states in both scenarios, and Samoa the least. Projected RCP 8.5 sea level rises reach about 0.81 m in 2100. As indicated for LME coastal countries, investing in education offers a strategic and long-term approach to reducing human vulnerability. It is particularly important for the Solomon Islands where education metrics such as mean years in school and the female tertiary educational attainment for present and projected scenarios are on the low end of the range. A long-term mitigation plan that answers to issues of habitability within the projected sea level rise scenarios is needed.


Island State	Present day	SSP1 (2100)	SSP3 (2100)
Fiji	0.5196	0.3804	0.4761
Samoa	0.3104	0.869	0.1265
Solomon Islands	0.5597	0.721	0.6549
Tonga	0.2395	0.869	0.2080
Vanuatu	0.2292	0.852	0.5090

Governance

Governance architecture:

The three transboundary arrangements for pollution and biodiversity that fall under the Noumea Convention are integrated under SPREP although there is a deficiency of protocols to give effect to the intent of the convention. The Pacific Islands Region has a well-structured mechanism for policy coordination and integration across all issues in the form of the Pacific Islands Forum. It is not clear that integration at the technical level is as well-structured, although there are many linkages and interaction among the relevant processes in this region, several of the supported by MOUs between agencies. The Western Pacific Warm Pool (WPWP) has been assigned an overall integration score of 1.0 due to the presence of the Pacific Islands Forum (PIF) with its ability to function as an overall policy coordinating organization for the key transboundary issues within the WPWP.
The overall scores for ranking of risk were: