Graham Martin (School of Biosciences, University of Birmingham, UK) and Rory Crawford (RSPB) have published an open-access review in the journal Global Ecology and Conservation on reducing bycatch of seabirds (including procellariiform species such as shearwaters) and other marine taxa in gill nets.  “[F]or gillnet bycatch to be reduced, the actual nets need to be made more visible to non-target vertebrates.”

The paper’s abstract follows:

“Sensory capacities and perceptual challenges faced by gillnet bycatch taxa result from fundamental physiological limits on vision and constraints arising within underwater environments.  To reduce bycatch in birds, sea turtles, pinnipeds and blue-water fishes, individuals must be alerted to the presence of nets using visual cues.  Cetaceans will benefit but they also require warning with cues detected through echolocation.  Characteristics of a visual warning stimulus must accommodate the restricted visual capacities of bycatch species and the need to maintain vision in a dark adapted state when foraging.  These requirements can be provided by a single type of visual warning stimulus: panels containing a pattern of low spatial frequency and high internal contrast.  These are likely to be detectable across a range of underwater light environments by all bycatch prone taxa, but are unlikely to reduce the catch of target fish species.  Such panels should also be readily detectable by cetaceans using echolocation.  Use of sound signals to warn about the presence of gillnets is not recommended because of the poor sound localisation abilities of bycatch taxa, cetaceans excepted.  These warning panels should be effective as a mitigation measure for all bycatch species, relatively easy to deploy and of low cost.”

Shearwaters: at risk to drowning in gill nets, Photograph by Vero Cortes

Reference: 

Martin, G.R. & Crawford, R, 2015.  Reducing bycatch in gillnets: A sensory ecology perspective.  Global Ecology and Conservation 3: 28-50.

John Cooper, ACAP Information Officer, 13 December 2014

A number of Marine Protected Areas offers at-sea protection to ACAP-listed albatrosses and petrels (click here).  All these MPAs or equivalents include within their boundaries islands or island groups which are breeding sites for one or more of the 30 ACAP-listed species. Several of them are situated in the North Pacific and Southern Oceans.

In recent years very large MPAs that are more than or approach 100 000 km² in size have been declared or expanded.  Eight of them that surround island groups supporting ACAP-listed species total over 3.34 million square kilometres.

In order of the year of their original designation these eight very large MPAs are:

Galapagos Marine Reserve, Ecuador, 1998, 133 000 km²

Macquarie Island Nature Reserve and Marine Park, Australia, 1999, 162 000 km²

Heard and McDonald Islands Marine Reserve, Australia, 2002 & 2014, 71 200 km²

Papāhanaumokuākea Marine National Monument, USA, 2006, 362 074 km²

Pacific Remote Islands Marine National Monument, USA, 2009 & 2014, 1 270 000 km²

South Orkney Islands Southern Shelf MPA, 2009, CCAMLR, 94 000 km²

South Georgia and South Sandwich Islands (Islas Georgias del Sur y Islas Sandwich del Sur)* MPA, disputed, 2010, 1 070 000 km²

Prince Edward Islands MPA, South Africa, 013, 180 000 km²

Overall, MPAs cover around one percent of the World’s oceans and seas.

John Cooper ACAP Information Officer,12 November 2014

*A dispute exists between the Governments of Argentina and the United Kingdom of Great Britain and Northern Ireland concerning sovereignty over the Falkland Islands (Islas Malvinas), South Georgia and the South Sandwich Islands (Islas Georgias del Sur y Islas Sandwich del Sur) and the surrounding maritime areas.

Raül Ramos (Department of Animal Biology, University of Barcelona, Spain) and colleagues have published this month in the journal The American Naturalist on the transference of antibodies from vaccinated female Cory's Shearwaters Calonectris borealis to their chicks via their egg yolks.

The paper’s abstract follows:

“Although little studied in natural populations, the persistence of immunoglobulins may dramatically affect the dynamics of immunity and the ecology and evolution of host-pathogen interactions involving vertebrate hosts.  By means of a multiple-year vaccination design against Newcastle disease virus, we experimentally addressed whether levels of specific antibodies can persist over several years in females of a long-lived procellariiform seabird—Cory’s shearwater—and whether maternal antibodies against that antigen could persist over a long period in offspring several years after the mother was exposed.  We found that a single vaccination led to high levels of antibodies for several years and that the females transmitted antibodies to their offspring that persisted for several weeks after hatching even 5 years after a single vaccination.  The temporal persistence of maternally transferred antibodies in nestlings was highly dependent on the level at hatching.  A second vaccination boosted efficiently the level of antibodies in females and thus their transfer to offspring.  Overall, these results stress the need to consider the temporal dynamics of immune responses if we are to understand the evolutionary ecology of host-parasite interactions and trade-offs between immunity and other life-history characteristics, in particular in long-lived species.  They also have strong implications for conservation when vaccination may be used in natural populations facing disease threats.”

Cory’s Shearwater and chick, photograph by Raül Ramos

Click here for a news article on the publication.

Reference:

Ramos, R., Garnier, R., González-Solís, J. & Boulinier, T. 2014.  Long antibody persistence and transgenerational transfer of immunity in a long-lived vertebrate.  The American Naturalist 184: 764-776.

John Cooper, ACAP Information Officer, 11 December 2014

The Biodiversity Research Institute (IRBio) and the Departament de Biologia Animal of the Universitat de Barcelona in Spain have recently posted a video documentary on seabird bycatch in the Mediterranean.  The 14-minute video entitled ‘Hams sense ocells’ appears in both Catalán and Spanish (Castellano) languages (click here).

The documentary, funded by the Fundacion Biodivesidad explains the problem of seabird bycatch along the Catalan coast and the need to adapt mitigation measures in the Mediterranean fishing fleet to reduce it.  Some mitigation trials have been funded by ACAP in its  last call for project funding (click here).

Click here for more information on the department’s programme on sea bird bycatch.

Yelkouan Shearwater at sea in the Mediterranean

With thanks to Jacob González-Solís for information.

John Cooper, ACAP Information Officer, 10 December 2014