Reciprocal Subsidies and Food Web Pathways Leading to Chum Salmon Fry in a Temperate Marine-Terrestrial Ecotone

Stable isotope analysis was used to determine the relative proportions of terrestrial and marine subsidies of carbon to invertebrates along a tidal gradient (low-intertidal, mid-intertidal, high-intertidal, supralittoral) and to determine the relative importance of terrestrial carbon in food web pathways leading to chum salmon fry Oncorhynchus keta (Walbaum) in Howe Sound, British Columbia. We found a clear gradient in the proportion of terrestrially derived carbon along the tidal gradient ranging from 68% across all invertebrate taxa in the supralittoral to 25% in the high-intertidal, 20% in the mid-intertidal, and 12% in the low-intertidal. Stable isotope values of chum salmon fry indicated carbon contributions from both terrestrial and marine sources, with terrestrially derived carbon ranging from 12.8 to 61.5% in the muscle tissue of chum salmon fry (mean 30%). Our results provide evidence for reciprocal subsidies of marine and terrestrially derived carbon on beaches in the estuary and suggest that the vegetated supralittoral is an important trophic link in supplying terrestrial carbon to nearshore food webs

A comprehensive approach for habitat restoration in the Columbia Basin

The Columbia Basin once supported a diversity of native fishes and large runs of anadromous salmonids that sustained substantial fisheries and cultural values. Extensive land conversion, watershed disruptions, and subsequent fishery declines have led to one of the most ambitious restoration programs in the world. Progress has been made, but restoration is expensive (exceeding US $300 M/year), and it remains unclear whether habitat actions, in particular, can be successful. A comprehensive approach is needed to guide cost-effective habitat restoration. Four elements that must be addressed simultaneously are (1) a scientific foundation from landscape ecology and the concept of resilience, (2) broad public support, (3) governance for collaboration and integration, and (4) a capacity for learning and adaptation. Realizing these in the Columbia Basin will require actions to rebalance restoration goals to include diversity, strengthen linkages between science and management, increase public engagement, work across traditional ecological and social boundaries, and learn from experience.This is the publisher’s final pdf. The published article is copyrighted by Taylor & Francis and can be found at: http://www.tandfonline.com/loi/ufsh20#.VUEib2MywS

The intertidal fish collections of Ed Ricketts at Tofino, British Columbia, Canada, 1945 and 1946

Few studies exist on the intertidal fish fauna of the west coast of Vancouver Island, British Columbia. The earliest known regional insights into intertidal fish diversity for the Tofino area were made by iconic marine ecologist Edward Flanders Ricketts. We reviewed his 1945 and 1946 collection cards, now available online. He made 111 collections of 20 species and 294 specimens. Most of these species were cottids (nine species) or pricklebacks (three species), with flatfish, greenlings, poachers, snailfish, gunnels, sand lance, and clingfishes each represented by one or two species. We briefly compare the data with contemporary studies and suggest opportunities for using his museum-curated physical specimens for further analyses

Ecology of salmonids in estuaries around the world : adaptations, habitats, and conservation [Book Supplement]

For centuries, biologists have marvelled at how anadromous salmonids – fish that pass from rivers into oceans and back again – survive as they migrate between these two very different environments. Yet, relatively little is understood about what happens to salmonid species (including salmon, steelhead, char, and trout) in the estuaries where they make this transition from fresh to salt water. This book explains the critical role estuaries play in salmonid survival. Ecology of Salmonids in Estuaries around the World synthesizes information from a vast array of literature, to: describe the specific adaptation of eighteen anadromous salmonids in four genera (Hucho, Oncorhynchus, Salmo, and Salvelinus); explain the ecological relationships between anadromous salmonids, the fish they coexist with, and their estuarine habitat; discuss key fitness elements salmonids need for survival in estuaries (including those relating to osmoregulation, growth and feeding mechanisms, and biotic interactions); provide guidance on how to conduct estuarine sampling and scientific aspects of conservation, management, and recovery plans; offer directions for future research. This critical reference is further enhanced by extensive supplementary appendices that are available to readers online, including data tables, additional references on estuarine salmonids, and a primer on estuaries and salmonids for citizen scientists.Science, Faculty ofResources, Environment and Sustainability (IRES), Institute forReviewedFacult

Aspects of the life history of Lycodopsis pacifica (Collett) 1879

Aspects of the life history of Lycodopsis pacifica (Collett) 1879 were studied during the period September 1965 to November 1966. Two areas in the Strait of Georgia, British Columbia, were investigated. Trawls were used as sampling devices. Sexually mature individuals were collected during the period September to January. Lycodopsis pacifica has a remarkably small complement of mature eggs (average complement 30.4), The mature eggs are large, with an average diameter of 5.0 mm. Sexual dimorphism is present. Males start to grow faster than females at approximately 170 mm in length. The older males are' larger than females. There is some evidence that parental care is involved in the reproductive behaviour of the species. Age was estimated by counting the annular rings on otoliths. Both males and females ranged up to five years of age. The age-length relationship for both sexes is presented. The length-weight relationship of the species is described. The food spectrum of Lycodopsis pacifica was determined. At outer Burrard Inlet, the species feeds primarily on infaunal invertebrates of the Phyla Mollusca and Annelida, and the Sub-phylum Crustacea, The place of L. pacifica in the bottom community is considered. The anatomy of structures associated with feeding are described. Visual and "chemical" senses are probably important in food-getting behaviour. The feeding adaptations and food of the species is discussed in relation to sediment type. L. pacifica is probably not specialized to remove infaunal food items from one type of sediment. It was assumed that Lycodopsis pacifica would aggregate where high concentrations of infaunal organisms suitable as food would be found. At outer Burrard Inlet, high numbers were caught on several sediment types, ranging from silt-sand to silt. At the Cape Lazo area, catches of L, pacifica were highest on a silt sediment. The species is likely capable of foraging on a range of sediment types. Some factors affecting the infauna are discussed, and the usefullness of simple mechanical analysis of sediments in benthic ecology is questioned.Science, Faculty ofZoology, Department ofGraduat

Stable isotope values of carbon (δ¹³C) and nitrogen (δ¹⁵N) and proportion of terrestrially derived carbon (TC) for consumers (invertebrates, fish).

<p>Shown are values for taxa by habitat (supralittoral, high-intertidal, mid-intertidal, low-intertidal) and common name/taxa and species name. Shown are the number of samples(n), the mean and standard deviation (SD) for δ¹³C and δ¹⁵N, the proportion of TC (%) including the mean, standard error (SE), and upper (U) and lower (L) 95 percentile confidence limits of TC calculated using the mixing model (Phillips and Gregg 2001). For chum salmon fry the minimum and maximum values of δ¹³C, δ¹⁵N, and TC are also shown.</p

Map of the British Columbia, the Strait of Georgia, and Howe Sound showing the two beaches (Furry Creek, North and South: FCN, FCS).

<p>Aerial image of Furry Creek showing the location of the two beaches on either side of the creek (© 2009. Google. Map Data. 2004 Tele Atlas).</p

Gut contents by fraction of total individuals and fraction of occurrence for 28 chum salmon fry.

<p>Shown is the taxa and life stage.</p

Carbon (δ¹³C) and nitrogen (δ¹⁵N) values of prey taxa in supralittoral, beach wrack, mid-intertidal and low-intertidal zones.

<p>Lines show taxa collected in more than two zones: Acariformes (hatched line), Diptera (dotted line), and Amphipoda (solid line). Values in brackets represent the fraction of terrestrially derived carbon (TC).</p