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© 2015 Elsevier Ltd Traditionally, the advice provided to fishery managers has focused on the trade-offs between short- and long-term yields, and between future resource size and expected future catches. The harvest control rules that are used to provide management advice consequently relate catches to stock biomass levels expressed relative to reference biomass levels. There are, however, additional trade-offs. Ecosystem-based fisheries management (EBFM) aims to consider fish and fisheries in their ecological context, taking into account physical, biological, economic, and social factors. However, making EBFM operational remains challenging. It is generally recognized that end-to-end modeling should be a key part of implementing EBFM, along with harvest control rules that use information in addition to estimates of stock biomass to provide recommendations for management actions. Here we outline the process for selecting among alternative management strategies in an ecosystem context and summarize a Field-integrated End-To-End modeling program, or FETE, intended to implement this process as part of the Bering Sea Project. A key aspect of this project was that, from the start, the FETE included a management strategy evaluation component to compare management strategies. Effective use of end-to-end modeling requires that the models developed for a system are indeed integrated across climate drivers, lower trophic levels, fish population dynamics, and fisheries and their management. We summarize the steps taken by the program managers to promote integration of modeling efforts by multiple investigators and highlight the lessons learned during the project that can be used to guide future use and design of end-to-end models.

In 1997, the Bering Sea ecosystem, a productive, high-latitude marginal sea, demonstrated that it responds on very short time scales to atmospheric anomalies. That year, a combination of atmospheric mechanisms produced notable summer weather anomalies over the eastern Bering Sea. Calm winds, clear skies, and warm air temperatures resulted in a larger-than-normal transfer of heat to surface waters and the establishment of a shallow mixed layer. In spring, significant new production occurred below the shallow pycnocline over the Middle Shelf, depleting the subpycnocline nutrient reservoir that normally exists during summer. Following the depletion of nitrate and silicate from the system, a sustained (≥ 4 months) bloom of coccolithophores (Emiliania huxleyi) was observed - a phenomenon not previously documented in this region. Summer Middle Shelf Domain copepod concentrations were higher for some species in 1997 than in the early 1980s. Warmer surface water and lack of wind mixing also changed the basic distribution of hydrographic regimes on the south-eastern shelf and altered the strength and position of fronts or transition zones where apex predators seek elevated food concentrations. The Inner Front was well inshore of its normal position, and adult euphausiids (the primary prey of short-tailed shearwaters, Puffinus tenuirostris) were unavailable at, and shoreward of, the front in autumn. High shearwater mortality rates followed the period of low euphausiid availability. Some, but not all, of these anomalous conditions re-occurred in 1998. These observations are another demonstration that the structure and function of marine ecosystems are intimately tied to forcing from the atmosphere. Alteration of climatological forcing functions, expressed as weather, can be expected to have large impacts on this ecosystem and its natural resources.

During summer 1997, hundreds of thousands of emaciated short-tailed shearwaters (Puffinus tenuirostris) died in the south-eastern Bering Sea. Using strip transect methodology, we documented the distribution and abundance of short-tailed shearwaters during cruises conducted prior to, during, and after the die-off, as well as the distributions and abundances of floating carcasses. The distributions and abundances of short-tailed shearwaters in 1997 were similar to those found during the 1970s and early 1980s. In August-September 1997, we observed 163 floating shearwater carcasses, most of which were between St Paul Island and Nunivak Island. We estimated ∼ 190 000 carcasses were afloat in the study area, about 11% of the surveyed population. Between spring (June) and autumn (August/September), mean net body mass of shearwaters decreased by 19%, mean pectoral muscle mass decreased by 14%, and mean percentage body lipid content decreased by 46%, from 15.6% in spring to 8.4% in autumn. Compared with spring, short-tailed shearwater diets broadened in autumn 1997, to include, in addition to adult euphausiids Thysanoessa raschii, juveniles of T. inermis, T. raschii and T. spinifera, crab megalops, fish and squid. We discuss how the ecosystem anomalies in the south-eastern Bering Sea during spring and summer 1997 relate to the mortality event and suggest possible implications of long-term climate change for populations of apex predators in the south-eastern Bering Sea.

Anomalies in the regional weather over the southeastern Bering Sea during spring and summer of 1997 resulted in significant differences in nutrient availability, phytoplankton species composition, and zooplankton abundance over the continental shelf as compared with measurements in the 1980s. Calm winds and the reduction of cloud cover in spring and summer produced a very shallow mixed layer in which nitrate and silicate were depleted after an April diatom bloom. High submarine light levels allowed subsequent phytoplankton growth below the pycnocline and eventual depletion of nitrate from the water column to depths of 70 m or more. Thus, total new production during 1997 may have exceeded that of previous years when nitrate was not depleted below the pycnocline. A bloom of the coccolithophorid, Emiliania huxleyi, was observed in early July in the warm, nutrient-depleted waters over the middle and inner shelf. Emiliania huxleyi concentrations reached 4.5 × 106cells L-1by September, and the bloom persisted through the autumn. There was evidence for increased abundance of some species of copepods in 1997 as compared with data from the middle domain in June 1981. The abundance of adult and juvenile euphausiids in 1997 was statistically similar to values measured in 1980 and 1981. However, near-surface swarms were rarely observed on the inner shelf in August-September 1997. Lack of euphausiid availability in the upper water column may partially explain the August-September mass mortality of planktivorous short-tailed shearwaters (Puffinus tenuirostris) observed on the inner shelf.

1. The foraging ecology of Brunnich's guillemots Uria lomvia was studied during the breeding season in south-eastern Svalbard. In the region of Storfjorden there are two large breeding colonies comprising a total of about 540 000 individuals. These birds forage in the western part of Storfjorden and further to the south. Their main prey: are polar cod Boreogadus saida, pelagic amphipods Parathemisto spp. and euphausiids Thysanoessa inermis. 2. A ship-based transect survey was used to record bird abundance and the acoustically determined biomass of presumed prey. The five transects were divided into 33 segments, each 8-11 km in length. The resolution of the survey was 150 m, and analyses of correlations between predators and prey were performed at length scales: from 150 m to 9 km. We differentiated acoustic signals into aggregated and dispersed categories according to the estimated horizontal distribution of presumed prey. 3. Foraging guillemots were consistently more strongly correlated with the aggregated prey than with dispersed prey over scales ranging from 150 m to 9 km. Correlations were weak at small scales (150 m - 1 km) and increased and stabilized at scales of 23 km. The spatial scale at which we obtained a shift from weak to strong correlations between guillemots and their prey was similar to the scale at which the spatial variances in both guillemot and prey abundance were high. 4. Guillemots showed low correlations with prey at low prey densities. Similarly, correlations between guillemots and prey were low at low bird densities. The data support the hypothesis that the birds associate with prey patches with densities above a certain threshold, and that 'regional' prey abundances affect local use of patches. 5. The numerical aggregative response curves between guillemot and prey density were classified as being neither hyperbolic (type II) or sigmoidal (type III) within the range of prey densities observed in this study. The aggregative response curves were sensitive to spatial scales, which suggest that studies of response curves should be conducted at a range of spatial scales.

Naive chicks of Gallus domesticus displayed a visually elicited pecking response to various stimuli with characteristics of both food and water drops; pecking was directed at small objects contrasting with their backgrounds, especially shiny, high-contrast targets. Chicks' drinking response was not elicited on initially seeing pools of water, and usually appeared only after water had been taken inside the bill. The preferred characteristics of targets for pecking would lead chicks to dew and rain drops, and provide 1 opportunity for learning the visible characteristics of water. Other opportunities are also available, and inheritance of an ability to respond with drinking to the 1st sight of water is apparently unnecessary. Most workers who have observed naive young of Gallus domesticus have commented on the variety of small objects at which the chicks peck, and have noted that this response to visible features of their environment leads the chicks to discover food. Lloyd Morgan (1896), Katz (1937), and others have noted that the same chicks failed to drink from pools of water, even when standing in them; seemingly, thus, chicks lack a response to the visible properties of water which will lead them to drink. Although it does not often seem to be visually elicited, naive chicks do have a motor pattern which has been called a drinking response, and which can usually be observed shortly after a chick first gets water within its bill. The purpose of these experiments was to determine why no drinking response is shown by naive chicks to the sight of pools of water, and to show that none is necessary. If one behavioral response will accomplish two physiological objectives with sufficient efficiency, natural selection will not necessarily operate to encode a second behavioral response if the economics of genetic encoding are restrictive. The experiments attempted to find some of the visual clues to which a chick responds and to show that these can lead it both to food and to water. Our concern is only with the visual clues

A survey of museum specimens revealed large interspecific variability in the sex ratio in 14 species [Mew, ring-billed, laughing, Franklin's, Bonaparte's, Heerman's, California, herring, Thayer's, western, glaucous, glaucous-winged, and great black-backed gulls, and blacklegged kittiwake] of North American gulls. In the three black-headed species, (Larus atricilla, L. pipixcan, and L. philadelphia), females outnumbered males among prefledglings, but males outnumbered females among adults. In the white-headed gulls, the male/female ratio in prefledglings did not vary significantly from 1.0 in any species. However, among first-year birds, females outnumbered males in 8 white-headed species. Among adults, the male/female ratio was < 1.0 in the Mew and Ring-billed gulls, > 1.0 in the Great Black-backed Gull, and = 1.0 in the other white-headed gulls.