Animal Counting Toolkit : a practical guide to small-boat surveys for estimating abundance of coastal marine mammals

The authors thank Synchronicity Earth, Marisla Foundation, and the US Marine Mammal Commission for seed funding for this program.Small cetaceans (dolphins and porpoises) face serious anthropogenic threats in coastal habitats. These include bycatch in fisheries; exposure to noise, plastic and chemical pollution; disturbance from boaters; and climate change. Generating reliable abundance estimates is essential to assess sustainability of bycatch in fishing gear or any other form of anthropogenic removals and to design conservation and recovery plans for endangered species. Cetacean abundance estimates are lacking from many coastal waters of many developing countries. Lack of funding and training opportunities makes it difficult to fill in data gaps. Even if international funding were found for surveys in developing countries, building local capacity would be necessary to sustain efforts over time to detect trends and monitor biodiversity loss. Large-scale, shipboard surveys can cost tens of thousands of US dollars each day. We focus on methods to generate preliminary abundance estimates from low-cost, small-boat surveys that embrace a ‘training-while-doing’ approach to fill in data gaps while simultaneously building regional capacity for data collection. Our toolkit offers practical guidance on simple design and field data collection protocols that work with small boats and small budgets, but expect analysis to involve collaboration with a quantitative ecologist or statistician. Our audience includes independent scientists, government conservation agencies, NGOs and indigenous coastal communities, with a primary focus on fisheries bycatch. We apply our Animal Counting Toolkit to a small-boat survey in Canada’s Pacific coastal waters to illustrate the key steps in collecting line transect survey data used to estimate and monitor marine mammal abundance.Publisher PDFPeer reviewe

Prioritizing global marine mammal habitats using density maps in place of range maps

RW collected the BC data with Raincoast Conservation Foundation, and was supported by a Marie Curie International Incoming Fellowship within the 7th European Community Framework Programme (proposal no. 253407 (call reference: FP7‐PEOPLE‐2009‐IIF)) during the analysis stage.Despite lessons from terrestrial systems, conservation efforts in marine systems continue to focus on identifying priority sites for protection based on high species richness inferred from range maps. Range maps oversimplify spatial variability in animal distributions by assuming uniform distribution within range and de facto giving equal weight to critical and marginal habitats. We used Marxan ver. 2.43 to compare species richness-based systematic reserve network solutions using information about marine mammal range and relative abundance. At a global scale, reserve network solutions were strongly sensitive to model inputs and assumptions. Solutions based on different input data overlapped by a third at most, with agreement as low as 10% in some cases. At a regional scale, species richness was inversely related to density, such that species richness hotspots excluded highest-density areas for all species. Based on these findings, we caution that species-richness estimates derived from range maps and used as input in conservation planning exercises may inadvertently lead to protection of largely marginal habitat.Publisher PDFPeer reviewe

Map of British Columbia inshore waters identifying major waterways.

<p>Map of British Columbia inshore waters identifying major waterways.</p

Audiograms of marine mammal species occurring in British Columbia.

<p>Audiograms of marine mammal species occurring in British Columbia.</p

A measure of audible acoustic energy from all classes of ships over the summer of 2008 by species on a 5×5 km grid.

<p>A measure of audible acoustic energy from all classes of ships over the summer of 2008 by species on a 5×5 km grid.</p

Audibility map for Dall's porpoise (left), Dall's porpoise density map (middle) and resulting map of hotspots (right).

<p>Audibility map for Dall's porpoise (left), Dall's porpoise density map (middle) and resulting map of hotspots (right).</p

Map of ship noise and animal hotspots for four odontocete species.

<p>Map of ship noise and animal hotspots for four odontocete species.</p

Map of ship noise and animal hotspots for baleen whales and pinnipeds.

<p>All color scales range from 0 (blue) to 1 (red), indicating least to highest risk.</p