Shawn Booth

Mercury, food webs, and marine mammals: implications of diet and climate change for human health.

We modeled the flow of methyl mercury, a toxic global pollutant, in the Faroe Islands marine ecosystem and compared average human methyl mercury exposure from consumption of pilot whale meat and fish (cod, Gadus morhua) with current tolerable weekly intake (TWI) levels. Under present conditions and climate change scenarios, methyl mercury increased in the ecosystem, translating into increased human exposure over time. However, we saw greater changes as a result of changing fishing mortalities. A large portion of the general human population exceed the TWI levels set by the World Health Organization [WHO; 1.6 μg/kg body weight (bw)], and they all exceed the reference dose (RfD) of 0.1 μg/kg bw/day set by the U.S. Environmental Protection Agency (EPA; equivalent to a TWI of 0.7 μg/kg bw). As a result of an independent study documenting that Faroese children exposed prenatally to methyl mercury had reduced cognitive abilities, pregnant women have decreased their intake of whale meat and were below the TWI levels set by the WHO and the U.S. EPA. Cod had approximately 95% lower methyl mercury concentrations than did pilot whale. Thus, the high and harmful levels of methyl mercury in the diet of Faroe Islanders are driven by whale meat consumption, and the increasing impact of climate change is likely to exacerbate this situation. Significantly, base inflow rates of mercury into the environment would need to be reduced by approximately 50% to ensure levels of intake below the WHO TWI levels, given current levels of whale consumption.

Fisheries Contributions to the Gross Domestic Product: Underestimating Small-scale Fisheries in the Pacific

In developing countries, official statistics, national accounts, and economic development initiatives generally focus on commercial, often exportoriented fisheries, which are often perceived to be the major economic contribution of fisheries. While small-scale, non-commercial fisheries, especially near-shore subsistence fisheries, have been recognized as fundamental for social, cultural, and food security reasons, their catches are seldom accounted for in official statistics. Thus, their contributions to the Gross Domestic Product (GDP) are often not taken into consideration. Previously undertaken catch timeseries reconstructions for small-scale coastal fisheries of two US flag island areas in the tropical Pacific (American Samoa and the Commonwealth of the Northern Mariana Islands [CNMI]) provided estimates of total catches for 1982-2002 (commercial and non-commercial) and suggested considerable discrepancies between reported (commercial) statistics and reconstructed (commercial plus noncommercial) estimates. We applied a valuation approach used by the Manila-based Asian Development Bank to the reconstructed catch data for non-pelagic species to estimate total near-shore fisheries contributions to national GDP using valueadded estimators for each fisheries sector in combination with available price data for the period 1982-2002. This suggested that the contributions of smallscale fisheries to GDP for these two island areas may have been underestimated by a factor of over five, and indicated that the non-commercial sector plays a more significant role in national accounts as contributors to GDP than currently assumed. This analysis should challenge existing perspectives of marginality of non-commercial fisheries sectors to developing countries in general and should give international development agencies, as well as local governments, pause to rethink their prioritization of fisheries development support.

From Mexico to Brazil : Central Atlantic fisheries catch trends and ecosystem models

Global fisheries are in a crisis, and so are the marine ecosystems upon which these fisheries depend. Major policy and management changes are required to halt and reverse the trends that have brought about this situation. Underlying these changes is the need for availability of data sets, pertaining to large areas, that unequivocally demonstrate any large-scale fisheries impacts on marine ecosystems. Not until recently have such secondary data begun to be assembled, although data sets have been available for some time upon which such demonstrations could be based. This applies particularly to the global fisheries statistics assembled and maintained by the Food and Agriculture Organization of the United Nations (FAO), which are assembled by large, arbitrary statistical areas (rather than by ecosystems), and which are not verified against local data sets. The present contribution documents a multi-pronged approach to develop and test a methodology for reconstructing historic catch time series (including misreported catches), and spatially assign these to ecosystems on a large spatial scale. This will serve as baselines for assessing the ‘health’ of ecosystems, and to evaluate the effects of fishing and management scenarios. Important components of this methodology are a global 1 An earlier version of this paper was presented at the Fisheries Project Planning Meeting of the Bejier International Institute of Ecological Economics, June 21-23, 1999 in Woods Hole, Mass. spatial catch allocation and mapping routine (www.seaaroundus.org), the Ecopath with Ecosim approach and software for constructing food web models of marine ecosystems (www.ecopath.org), and FishBase, an information system on the fish of the world (www.fishbase.org). Along with putting global fisheries data on a spatial ecosystem basis, these tools can greatly contribute to deepening our understanding of the ecosystem services upon which fisheries rely.

Marine fisheries catches in Arctic Alaska.

The Food and Agriculture Organization of the United Nations (FAO) provides global data on fisheries catches based on reports by member countries. Interestingly, for FAO Statistical Area 18 (Arctic), the USA reports no fish catches to the global community. In Alaska, it is the communities found north of Cape Prince of Wales that fall within FAO area 18. However, the State of Alaska’s Department of Fish and Game has collected time series of commercial data, and undertakes community fisheries subsistence studies that are temporally and spatially intermittent. At the regional level, the National Oceanic and Atmospheric Administration (NOAA, Alaska) do not report on either of these fisheries, as they take place within state waters. The Sea Around Us Project, at the University of British Columbia’s Fisheries Centre, undertakes catch reconstructions to account for discrepancies between globally reported and likely total catches. Our catch reconstruction includes both subsistence and commercial fisheries of marine and anadromous species from 1950-2006 for 15 coastal and near-coastal communities in arctic Alaska. Total catches over this time period were estimated to be 89,000 tonnes (196.2 million pounds), with subsistence catches contributing 54 % (48,200 tonnes or 106.4 million pounds), and commercial catches estimated at over 40,700 tonnes (89.8 million pounds). Subsistence catches averaged 847 tonnes·year-1 (1.8 million pounds·year-1, range: 589-1,139 tonnes·year-1). It is only since the late 1980s that subsistence catches have exceeded those from the 1950s, when there was a higher reliance on fisheries resources. Despite a small increase in subsistence catches, the human population has increased from approximately 3,550 to approximately 12,650, which resulted in per capita catch rates falling from 237 kg·person-1·year-1 (523 pounds·person-1·year-1) in 1950 to 78 kg·person-1·year-1 (171 pounds·person-1·year-1) in 2006. One of the main drivers for this was the decrease in the amount of fish used for dog feed, when the snowmobile replaced the dogsled as the main form of transportation. The more holistic historical perspective of total reconstructed fisheries catches presented here is important, in view of the impacts of global climate change, given the significance of these resources for the food security of arctic peoples.