Cetacean rapid assessment: An approach to fill knowledge gaps and target conservation across large data deficient areas

Abstract

1. Many species and populations of marine megafauna are undergoing substantial declines, while many are also very poorly understood. Even basic information on species presence is unknown for tens of thousands of kilometres of coastline, particularly in the developing world, which is a major hurdle to their conservation.2. Rapid ecological assessment is a valuable tool used to identify and prioritize areas for conservation; however, this approach has never been clearly applied to marine cetaceans. Here a rapid assessment protocol is outlined that will generate broad-scale, quantitative, baseline data on cetacean communities and potential threats, that can be conducted rapidly and costeffectively across whole countries, or regions.3. The rapid assessment was conducted in Tanzania, East Africa, and integrated collection of data on cetaceans from visual, acoustic, and interview surveys with existing information from multiple sources, to provide low resolution data on cetacean community relative abundance, diversity, and threats. Four principal threats were evaluated and compared spatially using a qualitative scale: cetacean mortality in fishing gear (particularly gillnets); cetacean hunting, consumption or use by humans; shipping related collision risk and noise disturbance; and dynamite fishing.4. Ninety-one groups of 11 species of marine mammal were detected during field surveys. Potentially the most important area for cetaceans was the Pemba Channel, a deep, high-current waterway between Pemba Island and mainland Africa, where by far the highest relative cetacean diversity and high relative abundance were recorded, but which is also subject to threats from fishing. 5. A rapid assessment approach can be applied in data deficient areas to quickly provide information on cetaceans that can be used by governments and managers for marine spatial planning, management of developments, and to target research activities into the most important locations.

Risks to biodiversity and coastal livelihoods from artisanal elasmobranch fisheries in a Least Developed Country: The Gambia (West Africa)

“…While a suite of high-resolution data would be ideal, obtaining these are not feasible in developing countries or LDCs with no, or very limited, local resources. In these situations, inexpensive techniques such as interviews and community-based monitoring can provide essential data on poorly-known marine vertebrate groups of economic and/or conservation importance, in Africa and elsewhere (Aylesworth et al 2017;Humber et al 2017;Braulik et al 2018). For elasmobranchs in the tropics and subtropics, surveys of ish markets, landing and processing sites have provided a relatively inexpensive source of invaluable data on biodiversity and isheries (e.g.…”

Distribution and Habitat Use of a Cryptic Small Cetacean, the Burmeister's Porpoise, Monitored From a Small-Scale Fishery Platform

“…Coastal cetaceans are exposed to a range of human activities including fisheries, aquaculture, shipping, pollution and climate change (Mann, 2000), yet for many species, still little is known about their abundance and distribution (Reeves et al, 2005;Read, 2008). Using a relatively low-cost monitoring tool (Braulik et al, 2018), our study provides a quantitative assessment of the distribution and habitat use of Burmeister's porpoise, adding substantially to the knowledge base of a "Data Deficient" species (Hammond et al, 2012). One of our key findings was that porpoises use a narrow coastal region (<50 km from the shore); indeed, their distribution studied here in the northern extent of their range completely overlaps the extent of a smallscale gillnet fishery.…”

“…Data collected from platforms-ofopportunity are generally not spatially or temporally randomized and so can present analytical challenges (Isojunno et al, 2012); nonetheless, in regions where traditional monitoring methods are prohibitively costly or logistically challenging, platformsof-opportunity may provide novel insights into relative spatial distributions of cetaceans (e.g., Kiszka et al, 2007;MacLeod et al, 2008). As SSF are ubiquitous in many of the world's coastal regions (Chuenpagdee et al, 2006;Pauly, 2006), fishing vessels could presumably be used as platforms for monitoring marine species, particularly in data deficient regions (Braulik et al, 2018).…”

Determining spatial use of the world's second largest humpback dolphin population: Implications for place‐based conservation and management

“…For free-ranging cetaceans, determination of important habitats is not only crucial to understanding several aspects of the ecology, dynamics and social structure of a population (Goetz et al, 2012;Ingram & Rogan, 2002), but also vital to effective place-based conservation and manage- an appropriate survey design in terms of spatial and temporal consideration is needed in informing and developing place-based management unit (Braulik et al, 2018;Cleguer, Grech, Garrigue, & Marsh, 2015;Filby, Stockin, & Scarpaci, 2017;Hartel et al, 2015). The previous study that informed the dolphin spatial use was based on a 4-month shortterm survey (Zhou et al, 2007), which did not cover the entire spatial use of humpback dolphins in this region.…”