Download or read book Structure and Dynamics of Northeastern Pacific Demersal Fish Assemblages written by Wendy Louise Gabriel and published by . This book was released on 1982 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt: Regions of similar species composition and groups of demersal fish species with similar distribution patterns from Cape Flattery, Washington to Point Hueneme from 50-250 fm (93-460 rn) were defined based on results of an agglomerative cluster analysis of National Marine Fisheries Service Rockfish Survey data taken during the summer of 1977. Three major site groups appeared: 1) an upper slope region extended from Juan de Fuca Canyon to Point Hueneme at depths of 100-250 fm (183-467 m); 2) a northern mid-shelf break region extended from Cape Flattery to Cape Blanco at depths of 55-187 fm (100-340 m); 3) a southern mid-shelf break region began inshore at Cape Flattery and extended to the shelf break from Cape Blanco to Point Hueneme at depths of 50-146 fm (91-267 m). These major site groups were subdivided into subregions, often along depth contours. Eight species groups appeared: a deepwater group (in site region 1 and parts of site region 2), including some ubiquitous species; a shallow water group, concentrated in the south (site region 3) and a shallow water group, concentrated in the north (site region 2) included the most abundant species. Five other groups included rarer species with more localized distributions. Diversity trends and relationships between composition of species groups and environmental factors were investigated using AIDN analysis of information and diversity and principal component, canonical correlation and factor analyses. Diversity decreased with depth, and was highest at the northern and southern ranges of the sample areas. Local low diversity values within latitudes were usually due to dominance by splitnose rockfish (Sebastes diploproa) in the south or Pacific hake (Merluccius productus) inshore between 38°N and 46°N. Diversity was relatively low in some assemblage regions between Cape Blanco and Cape Mendocino, an area of strong upwelling and narrow shelf. The effect on species group composition of a 50 fm (92 m) change in depth within a particular degree of latitude appears larger than the effect of a 10 change in latitude in many regions. Multivariate analyses extracted and clarified local patterns of latitudinal change in species groups from cluster analysis, which appeared most strongly related to latitude itself and onshore Ekman transport. Several hypotheses relating assemblage structure to oceanographic features are presented. Assemblage characteristics may change with depth in response to changing forms of available food and distance from inshore upwelling fronts; and with latitude in response to environmental uncertainty. Replicate surveys and analyses are desirable to measure the repeatability of assemblage structure, and eventually assess the natural range of variability in composition and spatial and temporal extent of species groups. A model is hypothesized to consider the relative influences of environmental variability and density dependence (among and within functional groups) on structure and dynamics of demersal fish assemblages of the California Current.
Download or read book Proceedings written by and published by . This book was released on 1989 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NOAA Technical Report NMFS written by and published by . This book was released on 1984 with total page 846 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Distribution and Relative Abundance of Pelagic Nonsalmonid Nekton Off Oregon and Washington 1979 84 written by Richard D. Brodeur and published by . This book was released on 1986 with total page 590 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sport Fishery Abstracts written by and published by . This book was released on 1991 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fisheries Review written by and published by . This book was released on 1991 with total page 808 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fishery Bulletin written by United States. National Marine Fisheries Service and published by . This book was released on 1997 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Ecology of Marine Fishes written by Larry G. Allen and published by Univ of California Press. This book was released on 2006 with total page 672 pages. Available in PDF, EPUB and Kindle. Book excerpt: “A masterful accomplishment—Allen, Pondella and Horn have assembled a talented team of experts who produce authoritative, up-to-date accounts. This book will be used as the primary text in many fish biology courses and as a valuable reference elsewhere. Here is a wealth of data waiting to be mined by legions of graduate students as they generate the new ideas that will motivate marine ecology for years.”—Peter Sale, Editor of Coral Reef Fishes: Dynamics and Diversity in a Complex Ecosystem "A copiously illustrated and comprehensive interpretation of the past, present, and future state of over 500 species of fishes in Californian waters. A compilation of virtually all the many important studies on the ecology of California marine fishes."—Bruce B. Collette, National Marine Fisheries Service and co-author of The Diversity of Fishes
Download or read book Feeding Relationships Within Assemblages of Nearshore and Mid continental Shelf Benthic Fishes Off Oregon written by Willard Waldo Wakefield and published by . This book was released on 1984 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Patterns in the Distribution of Demersal Fishes on the Upper Continental Slope Off Central California with Studies on the Role of Ontogenetic Vertical Migration in Particle Flux written by W. Waldo Wakefield and published by . This book was released on 1990 with total page 626 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Ecology written by William J. Resetarits and published by . This book was released on 2001 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experimentation is a dominant approach in contemporary ecological research, pervading studies at all levels of biological organization and across diverse taxa and habitats. Experimental Ecology assembles an eminent group of ecologists who synthesize insights from these varied sources into a cogent statement about experimentalism as an analytical paradigm, placing experimentation within the larger framework of ecological investigation. The book discusses diverse experimental approaches ranging from laboratory microcosms to manipulation of entire ecosystem, illustrating the myriad ways experiments strengthen ecological inference. Experimental ecologists critique their science to move the field forward on all fronts: from better designs, to better links between experiments and theory, to more realism in experiments targeted at specific systems and questions.
Download or read book Canadian Journal of Fisheries and Aquatic Sciences written by and published by . This book was released on 2000-10 with total page 1060 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Journal of Northwest Atlantic Fishery Science written by and published by . This book was released on 1980 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fishery Database written by and published by . This book was released on 1992 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Canadian Technical Report of Fisheries and Aquatic Sciences written by and published by . This book was released on 1985 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spatial and Temporal Characteristics of Bottom trawl Fish Assemblages of the Continental Shelf and Upper Slope of the Pacific Coast of the United States 1977 1992 written by Chadwick V. Jay and published by . This book was released on 1996 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: Twenty-three bottom-trawl fish assemblages were identified from the relative biomass of 33 dominant species that occurred in the National Marine Fisheries Services' triennial trawl surveys over the continental shelf and upper slope off California, Oregon, and Washington from 1977 to 1992. The assemblages accounted for about 70% of the total variation in species composition among 2,565 hauls. Although the assemblages persisted over the 15-yr study period and occurred within broad geographic boundaries, some had substantially different spatial distributions among surveys. The ability to differentiate assemblages across five environmental variables (latitude, depth, surface and bottom water temperatures, and surficial substrate) was low. The preponderance of hake-dominated assemblages throughout the study area suggests that Pacific hake (Merluccius productus) may play a large role in the dynamics of demersal fish communities off the west coast of the United States. The same data were used to establish general features regarding the abundance and distribution of the 33 dominant fish, and investigate intersurvey regional variation in species composition. Flatfish were generally widespread and at low density within areas of their occurrence. In contrast, rockfish were comparatively less widespread, and were at higher density within areas of their occurrence. Pacific hake, spiny dogfish, and sablefish were both widespread and occurred in high density. The greatest amount of variation in species composition occurred in the shallow shelf region off California, and the shallow and deep regions between Cape Mendocino and Cape Blanco. These regions corresponded to areas with the greatest amount of annual variation in upwelling. Contrary to upwelling, intersurvey variation in surface temperature did not appear to correspond to variation in species composition, but there was an unanticipated negative correlation between variation in bottom temperature and variation in species composition. Species composition was influenced in most regions by Pacific hake, spiny dogfish, and sablefish. A conceptual model was developed to explore the relationship between regional changes in a species' biomass, incidence, and density, and their potential affect on species composition. Empirical examination of the model was difficult. Five of six flatfish species (Pacific sanddab, rex sole, Pacific halibut, Dover sole, and English sole) exhibited a significant positive linear relationship between incidence and log-transformed biomass which is consistent with density-dependent habitat selection. There was evidence (albeit weak) from patterns in the occupancy of substrate types by these flatfish, that marginal habitats are associated with areas of mud for Pacific sanddab and areas of sand for rex sole, Pacific halibut, and Dover sole.
Download or read book Predictions Under Uncertainty written by Manuel do Carmo Gomes and published by St. John's, Nfld. : Institute of Social and Economic Research, Memorial University of Newfoundland. This book was released on 1993 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gomes, a biologist, draws on a study of commercial fish assemblages on the Grand Banks of Newfoundland to illustrate how uncertainty about the structure of ecological models confounds attempts to predict community dynamics over time; concluding that new adaptive management strategies may be needed to deal with this inherent uncertainty.
