Search results
(1 - 7 of 7)
- Title
- Entanglements of marine mammals and seabirds in central California and the north-west coast of the United States 2001-2005,
- Description
- Entanglement records for seabirds and marine mammals were investigated for the period 2001-2005. The entanglement records were extracted from databases maintained by seven organizations operating along the west coast of the United States of America. Their programmes included beach monitoring surveys, rescue and rehabilitation and regional pinniped censuses. Records of 454 entanglements were documented in live animals and in carcasses for 31 bird species and nine marine mammal species. The most frequently entangled species were Common Murres, Western Gulls and California sea lions. The entanglement materials identified were primarily fishing related. Entanglements were recorded every year suggesting that although the incidence level differs annually, entanglement is a persistent problem. It is recommended that each programme records details in standardized categories to determine entanglement material sources. Numbers of entanglements observed during these surveys are likely to be a conservative view of the actual entanglement rate taking place at sea. © 2009 Elsevier Ltd., Cited By (since 1996):9, Marine Mammals, Birds & Turtles, CODEN: MPNBA, ,
- Author
- Moore, Lyday, Roletto, Litle, Parrish, Nevins, Harvey, Mortenson, Greig, Piazza, Hermance, Lee, Adams, Allen, Kell
- Date
- 2009-01-01T00:00:00Z
- Title
- Prey and plastic ingestion of Pacific Northern Fulmars (Fulmarus glacialis rogersii) from Monterey Bay, California
- Description
- Marine plastic pollution affects seabirds, including Pacific Northern Fulmars (Fulmarus glacialis rodgersii), that feed at the surface and mistake plastic for prey or incidentally ingest it. Direct and indirect health issues can result, including satiety and possibly leading to inefficient foraging. Our objective was to examine fulmar body condition, identify cephalopod diet to species, enumerate and weigh ingested plastic, and determine if prey number and size were correlated with ingested plastics in beach-cast fulmars wintering in Monterey Bay California (2003, n= 178: 2007, n= 185). Fulmars consumed mostly Gonatus pyros, G. onyx, and G. californiensis of similar size for both years. We found a significant negative correlation between pectoral muscle index and average size of cephalopod beaks per stomach; a significant increase in plastic categories between 2003 and 2007; and no significant correlation between number and mass of plastic compared with number and size of prey for either year. © 2014 Elsevier Ltd.
- Author
- Donnelly-Greenan, Harvey, Nevins, Hester, Walker
- Title
- At-sea mortality of seabirds based on beachcast and offshore surveys,
- Description
- Although seabird population biology is relatively well studied, little data exists on mortality at-sea. Beached bird surveys are used to identify patterns of seabird mortality, but resulting patterns are difficult to interpret without corresponding data on at-sea density. We examined seabird mortality relative to at-sea density in Monterey Bay, California over 10 yr by integrating data from monthly beachcast seabird and offshore seabird censuses. Beachcast seabird numbers were relatively constant (mean 2.82 ± 0.31 seabirds km -1) throughout the year. At-sea seabird density (mean 148.9 ± 16.12 seabirds km-2) peaked in the summer upwelling period and was least in the winter Davidson period. A principal components analysis of seasonal climatic, prey availability, and anthropogenic variables for Monterey Bay derived 3 significant principal components (PCs) (explaining 70% of variance) characterized by storm activity and low prey availability (PC1), river discharge and krill abundance (PC2), and oiling (PC3). These principal components were used in detailed analyses of the 2 most abundant seabird species and indicate that sooty shearwater Puffinus griseus relative mortality is greatest during decreased productivity and increased storm activity. While relative mortality of common murres Uria aalge cannot be explained by the derived principal components, relative mortality increased in late winter when prey availability decreased concurrent with the annual increase in reproductive stress. Beachcast seabird data is difficult to interpret in isolation; however, when linked to at-sea densities of seabirds, it becomes a powerful tool to examine the relative impacts of oceanography and direct human perturbations on seabird demography. © Inter-Research 2009., Cited By (since 1996):1, Marine Mammals, Birds & Turtles, CODEN: MESED, ,
- Author
- Newton, Croll, Nevins, Benson, Harvey, Tershy
- Date
- 2009-01-01T00:00:00Z
- Title
- Chronic oiling of marine birds in California by natural petroleum seeps, shipwrecks, and other sources
- Description
- We assessed temporal and spatial patterns of chronic oiling of seabirds in California during 2005-2010, using data on: (1) live oiled birds reported to the Oiled Wildlife Care Network (OWCN) from throughout the state, and (2) dead oiled birds found during systematic monthly beached-bird surveys in central California. A mean of 245 (±141 SD) live miscellaneous oiled birds (not associated with known oil spills) were reported to the OWCN per year, and 0.1 oiled dead birds km-1 per month were found on beach surveys in central California. Chemical fingerprinting of oiled feathers from a subset of these birds (n = 101) indicated that 89% of samples tested were likely from natural petroleum seeps off southern and central California. There was a pronounced peak during late winter in the number of oiled birds reported in southern California, which we theorize may be related to large storm waves disturbing underwater seeps. © 2013., Marine Mammals, Birds & Turtles, Article in Press
- Author
- Henkel, Nevins, Martin, Sugarman, Harvey, Ziccardi
- Date
- 2014-01-01T00:00:00Z
- Title
- Beached birds and physical forcing in the California Current System,
- Description
- Seabirds have often been proposed as environmental indicators. Beached bird data may provide an additional data source and such data is efficacious because it can reliably be collected by volunteers. In addition to anthropogenic factors, such as oil spills, changes in the ocean-atmosphere can affect carcass beaching rate in 3 non-exclusive ways: (1) direct mortality following storms, (2) mortality via bottom-up food web processes, and (3) increase in carcass delivery due to shifts in surface water movement. We used data from 3 volunteer-based beached bird data sets collected within the California Current System (CCS) to (1) examine the level of response to anomalous ocean conditions in 2005 and (2) explore the degree to which long-term beaching patterns could be explained by one or more of our proposed mechanisms. In 2005, anomalous die-offs of Cassin's auklet Ptychorhamphus aleuticus and the rhinoceros auklet Cerorhinca monocerata occurred in the winter in Monterey. By spring, anomalous die-offs of Brandt's cormorant Phalacrocorax pencillatus and the common murre Uria aalge occurred throughout the CCS. Over the longer term, increases in beaching were associated with changes in the timing and intensity of upwelling and, secondarily, with zonal winds aloft - a potential proxy of shifts in pelagic community composition. These results suggest that a bottom-up food web mechanism best explains seabird beaching, at least in the spring. Correlations of local measures of storminess to seabird beaching rates were weak to non-existent. Correlations were much stronger at the California site (8 yr) and weaker to non-existent at the Oregon site (26 yr). Collectively, these data suggest that relationships between ocean physics and beached bird response may be site specific and/or may reflect choices live birds make vis-à-vis non-breeding distribution. © Inter-Research 2007., Cited By (since 1996):9, Marine Mammals, Birds & Turtles, CODEN: MESED, ,
- Author
- Parrish, Bond, Nevins, Mantua, Loeffel, Peterson, Harvey
- Date
- 2007-01-01T00:00:00Z
- Title
- Seabird bycatch in Alaska demersal longline fishery trials: A demographic summary,
- Description
- The seasonal and spatial demographics are summarized for seabirds killed incidentally during gear modification trials for a demersal longline fishery in the Bering Sea. We examined 417 carcasses, including Northern Fulmar Fulmarus glacialis (n = 205), Glaucous-winged Gull Larus glaucescens (n = 103), Short-tailed Shearwater Puffinus tenuirostris (n = 48), Glaucous Gull Larus hyperboreus (n = 23), Slaty-backed Gull Larus schistisagus (n = 4), Black-legged Kittiwake Rissa tridactyla (n = 1), Laysan Albatross Diomedea immutabilis (n = 1), and unidentified gull species Larus spp. (n = 32). There was a significant male bias in the sex ratio of fulmars but not of gulls or shearwaters. For the top three species killed, the age composition of resident species was dominated numerically by adults (Northern Fulmar-86%; Glaucous-winged Gull-63%), whereas migrant species were primarily immature birds (Short-tailed Shearwater-71%). The majority of migratory Short-tailed Shearwaters (88%) were caught in July and August, whereas 70% of resident fulmars and gulls were caught in October and November. Age-class frequencies did not differ by month of capture, indicating that adult mortality is substantial. Eighty percent of the fulmars caught during July and August were within 200 km of two colonies in the Bering Sea, whereas only 7% of fulmars were caught in the same area during September to November. This is one of the first demographic summaries of seabird bycatch in Alaska longline fisheries. Additional studies of the species, age and sex of seabirds subject to fisheries-related mortality will provide data necessary to evaluate population-level impacts., Cited By (since 1996):1, ,
- Author
- Phillips, Nevins, Hatch, Ramey, Miller, Harvey
- Date
- 2010-01-01T00:00:00Z
- Title
- Seabirds indicate plastic pollution in the marine environment: Quantifying spatial patterns and trends in Alaska
- Description
- Downloaded from: http://seagrant.uaf.edu/bookstore/pubs/AK-SG-09-01.html (1 August 2014).
- Author
- Hyrenbach, Nevins, Hester, Keiper, Harvey, Williams, Ammann
- Date
- 2009-01-01T00:00:00Z