Rebecca Lewison (Department of Biology, San Diego State University, California, USA) and colleagues identify taxa-specific hotspots for fisheries bycatch of seabirds, marine mammals and turtles in the Proceedings of the National Academy of Sciences of the United States of America (PNAS).  “This analysis provides an unprecedented global assessment of the distribution and magnitude of air-breathing megafauna bycatch, highlighting its cumulative nature and the urgent need to build on existing mitigation successes.”

The paper’s abstract follows:

“Recent research on ocean health has found large predator abundance to be a key element of ocean condition.  Fisheries can impact large predator abundance directly through targeted capture and indirectly through incidental capture of nontarget species or bycatch.  However, measures of the global nature of bycatch are lacking for air-breathing megafauna.  We fill this knowledge gap and present a synoptic global assessment of the distribution and intensity of bycatch of seabirds, marine mammals, and sea turtles based on empirical data from the three most commonly used types of fishing gears worldwide.  We identify taxa-specific hotspots of bycatch intensity and find evidence of cumulative impacts across fishing fleets and gears. This global map of bycatch illustrates where data are particularly scarce—in coastal and small-scale fisheries and ocean regions that support developed industrial fisheries and millions of small-scale fishers—and identifies fishing areas where, given the evidence of cumulative hotspots across gear and taxa, traditional species or gear-specific bycatch management and mitigation efforts may be necessary but not sufficient.  Given the global distribution of bycatch and the mitigation success achieved by some fleets, the reduction of air-breathing megafauna bycatch is both an urgent and achievable conservation priority.”

Black-browed Albatrosses gather behind a trawler in the South Atlantic

Photograph by Graham Parker

Reference:

Lewison, R.L., Crowder, L.B., Wallace, B.P., Moore, J.E., Cox, T., Zydelis, R., McDonald, S., Di Matteo, A., Dunn, D.C., Kot, C.Y., Bjorkland, R., Kelez, S., Soykan, C., Stewart, K.R., Sims, M., Boustany, A., Read, A.J., Halpin, P., Nichols, W.J. & Safina, C. 2014.  Global patterns of marine mammal, seabird, and sea turtle bycatch reveal taxa-specific and cumulative megafauna hotspots.  Proceedings of the National Academy of Sciences of the United States of America.  doi/10.1073/pnas.1318960111.

John Cooper, ACAP Information Officer, 14 April 2014

Caio Cipro (Littoral Environnement et Sociétés, Université de La Rochelle, France) and colleagues have published in the journal Polar Biology on trace elements in tissues of White-chinned Petrels Procellaria aequinoctialis in the southern Indian Ocean.

The paper’s abstract follows:

“The use of seabirds to assess marine contamination by trace elements in areas remote from pollutant emission points has already been done at various latitudes. Nevertheless, little information is available concerning the Southern Indian Ocean. Determining the contaminants levels, there appears necessary not only due to several deleterious effects reported in literature, but also as previous studies have highlighted elevated concentrations of cadmium (Cd) and mercury (Hg) in mollusks, crustaceans and fish.  Within this context, the white-chinned petrel appears as a key species due to its lifespan, diet and trophic position.  Thirty-three accidentally killed (collision with lights/bycatch in longline vessels) individuals collected in Kerguelen waters were analysed for Cd, copper (Cu), Hg, selenium (Se) and zinc (Zn) in liver, kidney, pectoral muscle, feathers and for mature males, testis. Elevated Hg concentrations (average 58.4 μg g⁻¹ dw in liver) are likely due to the presence of mesopelagic prey in the diet of Procellaria aequinoctialis.  Cd concentrations (average of 65.7 μg g⁻¹ dw in kidney) can be attributed to a high level of fisheries offal consumption, as well as crustacean and squid ingestion. Correlation of Hg with Se indicates its detoxification by co-precipitation, and correlation of Cd with Zn suggests its displacement by Cd on metallothioneins binding sites.  This work also indirectly confirms ecological data (range and diet composition) from the wintering period of the species, which is [sic] rather scarce. Seasonal diet change and moulting accounted more for the obtained results than sex of the birds.”

A White-chinned Petrel falls the victim of a longline hook

Photograph by Nicolas Gasco

Reference:

Cipro, C.V.Z., Cherel, Y., Caurant, F., Miramand, P., Méndez-Fernandez, P. & Bustamante, P. 2014.  Trace elements in tissues of white-chinned petrels (Procellaria aequinoctialis) from Kerguelen waters, Southern Indian Ocean.  Polar Biology DOI 10.1007/s00300-014-1476-z.

John Cooper, ACAP Information Officer, 13 April 2014

Marina Codina-García (Departament de Biologia Animal, Universitat de Barcelona, Spain) and colleagues write in the Marine Pollution Bulletin on plastic loads in three species of Mediterranean shearwaters recovered from longlines.  One of the species studied, the Critically Endangered Balearic Shearwater Puffinus mauretanicus, is listed within ACAP, the other two are potential candidate species for listing.

The paper’s abstract follows

“Plastic debris is often ingested by marine predators and can cause health disorders and even death.  We present the first assessment of plastic ingestion in Mediterranean seabirds.  We quantified and measured plastics accumulated in the stomach of 171 birds from 9 species accidentally caught by longliners in the western Mediterranean from 2003 to 2010.  Cory’s [=Scopoli's] shearwaters (Calonectris diomedea) showed the highest occurrence (94%) and large numbers of small plastic particles per affected bird (on average N= 15.3 ± 24.4 plastics and mass = 23.4 ± 49.6 mg), followed by Yelkouan shearwaters (Puffinus yelkouan, 70%, N= 7.0 ± 7.9, 42.1 ± 100.0 mg), Balearic shearwaters (Puffinus mauretanicus, 70%, N= 3.6 ± 2.9, 5.5 ± 9.7 mg) and the rest of species (below 33%, N= 2.7, 113.6 ± 128.4 mg).  Plastic characteristics did not differ between sexes and were not related to the physical condition of the birds.  Our results point out the three endemic and threatened shearwater species as being particularly exposed to plastic accumulation.”

Yelkouan Shearwater

Click here for a report on the study.

Reference:

Codina-García, M., Militão, T., Moreno, J. & González-Solís, J. 2013.  Plastic debris in Mediterranean seabirds.  Marine Pollution Bulletin 77: 220-226.

John Cooper, ACAP Information Officer, 12 April 2013

Karine Delord (CEBC-CNRS, Villiers-en-bois, France) and colleagues have published in the journal Marine Policy on selecting candidate marine IBAs utilizing seabird-tracking data in the southern Indian Ocean.  ACAP-listed species included in the data set are Wandering Albatross Diomedea exulans, Amsterdam Albatross D. amsterdamensis, Indian Yellow-nosed Albatross Thalassarche carteri, White-chinned Petrel Procellaria aequinoctialis and Grey Petrel P. cinerea.

The paper’s abstract follows:

“Seabirds are increasingly threatened worldwide, with population declines for many species that are faster than in any other group of birds.  Here the Important Bird Area (IBA) criteria recommended by BirdLife International were applied to a large tracking dataset collected from a range of seabirds, to identify areas of importance at an ocean basin scale.  Key areas were identified using tracks obtained from both the breeding and non-breeding periods of 10 species that have different habitat requirements.  These species range in their IUCN threat status from Least Concern to Critically Endangered.  An evaluation of spatial overlap between the key areas for these species and the jurisdiction of Regional Fisheries Management Organisations (RFMOs), national Exclusive Economic Zones (EEZs) and other stakeholder bodies highlighted the major importance of the French EEZs (around Crozet, Kerguelen and Amsterdam Islands) for seabird conservation.  The majority of the candidate marine IBAs that were identified were located in the High Seas, where Marine Protected Areas cannot easily be designated under existing international agreements, except in the Commission for the Conservation of Antarctic Marine Living Resources Convention Area.  In the short term, it seems that only fisheries regulations (through international agreements) can bring about efficient protection for seabirds in the High Seas.  The BirdLife IBA approach, although sensitive to heterogeneity in the data (species selected, inclusion of different life stages, years etc.), proved valuable for selecting important areas corresponding to large-scale oceanographic structures that are considered to be key foraging habitats for many species.”

Wandering Albatrosses display on Ile de la Possession, Iles Crozet

Photograph by Franck Theron

With thanks to Richard Phillips for information.

Reference:

Delord, K., Barbraud, C., Bost, C.-A., Deceuninck, B., Lefebvre, T., Lutz, R., Micol, T., Phillips, R.A., Trathan, P.N. & Weimerskirch, H. 2014.  Areas of importance for seabirds tracked from French southern territories, and recommendations for conservation.  Marine Policy 48: 1-13.

John Cooper, ACAP Information Officer, 11 April 2014