1) to assess the spatial and temporal distribution of preindustrial herring abundance. Here, we compile the archaeological record of fisheries in the Northeast Pacific from Alaska, British Columbia, and Washington ( Fig. Such data provide both the long-term perspective needed to assess preindustrial ecological states, and ecologically and culturally salient baselines for conservation ( 22 – 24). As a result, traditional and local ecological knowledge, as well as paleoecological and archaeological data, are increasingly important for informing these baselines ( 21). Most modern ecological data lack sufficient time depth for establishing baselines for marine ecosystem management and recovery ( 19) this has the potential to dramatically underestimate the degree of population loss and inhibit recovery efforts. However, current knowledge of Pacific herring distribution and abundance is based on biomass estimates that date back only to the mid 20th century, well after the onset of industrial fishing.
#NOOTKA SOUND FISHING REPORT 2012 DRIVERS#
Assessing these potential drivers and moving forward with conservation requires baseline information on herring abundance and distribution before its depletion. These factors include climate-induced ecological changes in distribution of predators and prey ( 7), disease ( 17), overfishing ( 18), and the rebound of marine mammal populations that prey on herring ( 15). Fisheries scientists have proposed various factors accounting for these declines and sustained low abundances even after reductions of fishing pressure. Populations of this once highly abundant forage fish have been dramatically reduced across much of its North Pacific range relative to levels seen in the mid 20th century ( 14 – 16). Since 1882 and continuing into recent decades, industrial fishing of herring has helped support many communities across the Northwest Coast ( 13, 14). Herring is also central to the social, cultural, and economic relations of coastal indigenous communities, many of which seek to continue their traditional fisheries for herring and herring roe on kelp or other substrates ( 10 – 12). Herring and its roe are critical prey for a host of fish (e.g., hake, Pacific cod, dogfish, salmon), birds, and marine mammal predators ( 7 – 9). Both indigenous and nonindigenous peoples on the Northwest Coast of North America recognize Pacific herring ( Clupea pallasii) as a foundation species in coastal food webs ( 4) that serve an essential role in maintaining social-ecological systems (e.g., refs. Low trophic-level fish (“forage fish”) are experiencing global declines, with increasing recognition of widespread and cumulative ecological, cultural, and economic impacts ( 1 – 3). These results provide baseline information prior to herring depletion and can inform modern management. In either case, sufficient herring was consistently available to meet the needs of harvesters, even if variability is damped in the archaeological record. We are unable to distinguish between the second two hypotheses, which both assert that the archaeological data reflect a higher mean abundance of herring in the past, but differ in whether variability was similar to or less than that observed recently. We reject the first hypothesis that the archaeological data overestimate past abundance and underestimate past variability. We pose three alternative hypotheses to account for the disjunction between modern and archaeological herring populations. Analyses of temporal variability in 50 well-sampled sites reveals that herring exhibits consistently high abundance (>20% of fish bones) and consistently low variance (<10%) within the majority of sites (88% and 96%, respectively). Herring bones are archaeologically abundant in all regions, but are superabundant in the northern Salish Sea and southwestern Vancouver Island areas. Herring is the single-most ubiquitous fish taxon (99% ubiquity) and among the two most abundant taxa in 80% of individual assemblages. The dataset represents 435,777 fish bones, dating throughout the Holocene, but primarily to the last 2,500 y. We assembled data on fish bones from 171 archaeological sites from Alaska, British Columbia, and Washington to provide proxy measures of past herring distribution and abundance. Pacific herring ( Clupea pallasii), a foundation of coastal social-ecological systems, is in decline throughout much of its range.
0 kommentar(er)
