Johanna Pierre and colleagues (Dragonfly Data Science) have produced a draft report for the Conservation Services Programme of the New Zealand Department of Conservation on cryptic mortality of seabirds in New Zealand longline and trawl fisheries.

Painting of deployed bird-saving lines by Bruce Pearson

The report’s executive summary follows:

“Understanding the nature and extent of interactions between commercial fisheries and marine protected species is one component of best practice fisheries management.  These interactions can lead to mortalities of protected species, which may be detected (e.g., by fisheries observers on vessels), or not readily detectable, and undetected (also known as cryptic mortalities). For seabirds, cryptic mortalities may result, for example, when a bird carcass falls into the water after striking a trawl warp, or when a bird is landed alive on deck, removed from fishing gear and released, but later dies as a result of injuries sustained.  The assessment of the risk that New Zealand commercial fisheries represent to seabird populations, conducted by Richard & Abraham (2013), considers cryptic mortality using a set of multipliers applied across the various fishing methods.  These scalars are derived from sources including data collected in New Zealand and internationally.

Here, we draw on Richard & Abraham’s (2013) approach, updated in 2014, to identify seabird species and fisheries for which cryptic mortality contributes particularly strongly to the overall assessed risk.  We review assumptions and uncertainties inherent in Richard & Abraham’s (2014) methods, as well as relevant new information which may contribute to the development of more robust cryptic mortality scalars applicable to New Zealand fisheries.  Finally, we recommend options to improve the estimation of cryptic mortality for the seabird species groups and fisheries where this is particularly important.

From Richard & Abraham’s (2014) assessment, cryptic mortality was especially influential in determining overall assessed risk for both albatross and petrel species, including black petrel (Procellaria parkinsoni) interacting with small-vessel surface and bottom longline fisheries, and Salvin’s (Thalassarche salvini) and New Zealand white-capped (T. cauta steadi) albatross interacting with small inshore trawl vessels, and southern Buller’s albatross (T. bulleri bulleri) interacting with large trawl vessels with meal plants.  Key assumptions included that cryptic mortality scalars derived from fisheries outside New Zealand were appropriately applied to the New Zealand context despite differences in seabird assemblages, fishing operations and gear.  Further, scalars applied to cryptic mortality of seabirds due to aerial warp strikes and interactions with trawl nets were entirely assumption-based.

Relevant new information that may contribute to refining scalars describing cryptic mortality includes work conducted on cryptic mortality associated with a Falkland Islands demersal trawl fishery, and two new studies reporting the outcomes of seabird strikes on trawl warps.  Additional data sources that could prove valuable for the development of improved scalars include the database collected on seabird interactions with trawl fisheries in the Conservation of Antarctic Marine Living Resources Convention Area and from trawl fisheries off the Falkland Islands.  Given the seabirds and fisheries for which cryptic mortality is a particularly important determinant of overall risk, and the additional information that may be available, priority areas for improving estimates of cryptic mortalities in New Zealand fisheries include developing method-specific cryptic mortality scalars for bottom longline fisheries, exploring existing information to refine scalars applicable to inshore fisheries, and refining estimates of mortalities – both observed and cryptic - that result from aerial warp strikes.  Applying scalars for broad groupings of large (i.e., predominantly albatrosses) and small seabirds appears appropriate given current information. The immediate amendment of data collection protocols used by New Zealand fisheries observers is recommended to document cryptic seabird mortalities.  The implementation of new data collection protocols, potentially combined with experimental data collection, are also considered priorities in order to develop an understanding of cryptic mortality, especially in inshore fisheries.”

Reference:

Pierre, J.P., Richard, Y. & Abraham, E.R. 2014.  Assessment of Cryptic Seabird Mortality due to Trawl Warps and Longlines.  Draft Report prepared for the Department of Conservation: Conservation Services Programme Project INT2013-05.  Wellington: Dragonfly Data Science.  46 pp.

John Cooper, ACAP Information Officer, 26 November  2014

Barry Baker, Katrina Jensz and Ross Cunningham (Latitude 42 Environmental Consultants) have produced a draft final report for the Conservation Services Programme of the New Zealand Department of Conservation detailing population trends in Near Threatened White-capped Albatrosses Thalassarche steadi breeding on New Zealand’s Auckland Island Group, including on Adams and Disappointment Islands.

A White-capped Albatross guards its chick, photograph by David Thompson

The report’s executive summary follows:

“White-capped albatrosses Thalassarche steadi are endemic to New Zealand, breeding on Disappointment Island, Adams Island and Auckland Island in the Auckland Island group, and Bollons Island (50-100 pairs) in the Antipodes Island Group.  Population estimates suggest most (95%) of the global population breeds on Disappointment Island, an area where access is restricted to maintain environmental values at the site.  Virtually all aspects of the biology and ecology of white-capped albatrosses are poorly known and although approximate population sizes have developed there have been no well-documented population estimates for any of the colonies until this study.

Between 2006/07 and 2013/14 (hereinafter 2006 and 2013, respectively) we undertook repeated population censuses of the white-capped albatrosses breeding in the Auckland Islands using aerial photography. These population censuses were carried out in either December or January each year to estimate population size and track population trends.

In 2013 we estimated that there were 89,552 (95%CI 88,953 — 90,151), 5,542 (5,393 — 5,691) and 184 (157— 211) annual breeding pairs at Disappointment Island, South West Cape and Adams Island, respectively, based on the raw counts, giving a total for these sites of 95,278 (94,661 — 95,895) breeding pairs.

To assess population trend in total counts we used an appropriate Generalised Linear Model where the response was specified as an over dispersed Poisson distribution and the link was logarithmic.  To allow for possible non-linear trend effects we used regression splines with a single knot at 2010.  We also assessed trend using software program TRIM (TRends and Indices for Monitoring Data), the standard tool used by the Agreement for the Conservation of Albatrosses and Petrels (ACAP).

Evidence from a series of ‘close-up’ photographs taken each year (2007-2013) indicates that the number of non-breeding birds present in the colonies differed somewhat between December and January.  The proportion was very low in December counts (1-2% of birds present), but higher in the January counts (14% of birds present).  Estimated annual counts for all three breeding sites in the Auckland Islands were adjusted to account for the presence of non-breeding birds, giving adjusted estimates of annual breeding pairs of 116 025, 90 036, 96 118, 73 838, 76 119, 92 692, 102 273 and 74 031 for each year from 2006 to 2013 inclusive.  These adjusted figures were used as inputs into models used for assessment of population trend.

Trend analysis for all sites combined using regression splines showed no clear evidence for systematic monotonic decline over the 8 years of the study.  This is particularly so if the count for 2006 is excluded.  Given this we do not have sufficient evidence to reject the null hypothesis of no systematic trend in the total population.  The population size estimates computed from the TRIM model indicate an average growth rate of -3.16% per year (λ = 0.9684 ± 0.001; assessed by TRIM as moderate decline. We note, however, that a simple linear trend analysis, as performed by TRIM is not well suited to a data set with high inter-annual variability.  Trend analysis using regression splines is more appropriate to such data sets, and the TRIM analysis is only presented because it is currently used by ACAP to assess population trends in albatross populations.

In a global review of fisheries-related mortality of shy and white-capped albatrosses it was estimated that 8,000 white-capped albatrosses were killed each year as a result of interactions with trawl and longline fisheries in the Southern Ocean. This level of mortality highlights the need to continue to acquire accurate population estimates and trends for white-capped albatross populations to assess the impact of fisheries operations on this species. Although annual counts over the last eight years indicate the population is stable, ongoing population monitoring is recommended to clarify if current levels of fishing mortality remain sustainable.”

Reference:

Baker, G.B., Jensz, K. & Cunningham, R. 2014.  White-capped Albatross Aerial Survey 2014 Draft Final Report.  Report prepared for Department of Conservation Contract 4523/4524. [Kettering]:  Latitude 42 Environmental Consultants Pty Ltd.  19 pp.

John Cooper, ACAP Information Officer, 25 November 2014

Both the final-phase and intermediate-phase plumaged Short-tailed Albatrosses Phoebastria albatrus that make up a female-female pair have been sighted at their nest site near the west end of Green Island, Kure Atoll in the North Pacific this season.  They were first reported with two eggs in their nest, but one was later displaced.

The banded female-female pair has laid two eggs on Kure each year since 2010 (click here), although none has ever hatched, so the eggs are presumed to be unfertilized.

Other Short-tailed Albatrosses are occasionally seen on Kure (click here).  Decoys have now been placed near the nest site with the hope of attracting more birds to the atoll.

The intermediate-plumaged of the pair with an overlooking decoy

Five decoys in a displaying position, with the female-female pair in the background

The adult-plumaged bird looks at a decoy, with five more in the background, along with Black-footed and Laysan Albatrosses

Photographs by the Kure Atoll Conservancy

With thanks to the Kure Atoll Conservancy.

John Cooper, ACAP Information Officer, 24 November 2014

Philippa Wallace has been awarded her Doctor of Philosophy in Law by The University of Waikato for a study of how New Zealand domestic and international conservation law affects the nation’s threatened birds.  Her thesis considers in detail the ACAP-listed and both nationally and globally Vulnerable Black Petrel Procellaria parkinsoni and the Sooty Shearwater Puffinus griseus in two of the six case studies covered.

Chapter Six of the thesis “Distribution of benefit and harm to species through law and planning in New Zealand - international obligations” inter alia considers the role of the Albatross and Petrel Agreement in helping conserve New Zealand’s Black Petrel.

Black Petrel at sea, photograph by Biz Bell

The abstract of the PhD thesis follows:

“Endemic birds in New Zealand are under threat, and increasingly so, as human activity reshapes the land, reconstitutes the water, consumes space and resources and alters faunal composition.  The decline of biodiversity is a pressing concern globally and the unique nature of the endemic fauna of New Zealand provides impetus for concern.

Examination of the state of birds and analysis of the response of New Zealand law to the agents of decline is the key contribution of this research.  The substance and operation of New Zealand law is examined to determine its influence upon the distribution of benefit and burden to New Zealand birds.  Six case study birds: the black petrel, dotterel, kokako, godwit, sooty shearwater, and the wrybill are studied to elucidate these matters.

In examining distribution of harm and benefit, a particular focus of the research is upon the degree of care that is applied to protecting birds through the law and related planning instruments.  By assessing the principles, criteria and methods applied to protecting birds, the research identifies that an objective of avoidance of harm to indigenous Threatened or At Risk species, their habitats, and ecosystems upon which they depend, will benefit birds.  It concludes that conservation status, as opposed to habitat or sectoral dispensation, is an important determinant for application of the standard, as this provides the most consistently protective approach.  In addition, it is demonstrated that where uncertainty or ignorance arises as to existence or level of harm, the use of precaution and giving the benefit of the doubt to nature is important for enhancing protection.

New Zealand conservation law is analysed at the international level in conjunction with species and habitat protection at the domestic level.  International agreements, the Wildlife Act 1953, the Conservation Act 1987, the Resource Management Act 1991 and related policy and plans are examined.  Although at times strongly beneficial, the research concludes that the arrangements made by the law are wanting.  An important contribution of the research is to demonstrate the deficiencies, which can be separated into three classes: the problem of standard, the problem of consistency and integration, and the problem of implementation.

These problems constrain the protective force of the law.  Fragmentation and lack of a strong and consistent protective standard limit protection of birds against competing social, economic and cultural factors.  The law requires revision.  Species protection calls for particular attention.  The Wildlife Act 1953 maintains a standard of absolute protection of birds, but the research demonstrates the many ways in which this standard is compromised.  Greater strategic planning and integration is required, particularly with regard to human development.  Interrelationships between the statutes, including that between the Wildlife Act 1953 and the RMA 1991, require addressing.  Inadequate implementation of existing law compounds these matters, and the research identifies a range of aspects where gains for species could be made.  It concludes with a series of recommendations directed at the identified problems.”

Reference:

Wallace, P.J. 2014.  Boundaries of Absolute Protection: Distribution of Benefit and Harm to Birds through Law and Planning in New Zealand.  PhD Thesis, The University of Waikato.  528 pp.

John Cooper, ACAP Information Officer, 23 November 2014