Project Update

Trade in mislabeled endangered sharks

Twelve species of endangered pelagic sharks are currently listed on Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). This global treaty aims to regulate the international trade of wildlife, however, as discussed by Prof David Sims (MMMAP Core Researcher) & Dr Matthew Frost in an article published in Science Letters earlier this year, appears to be doing little to stem the illegal harvesting of sharks.

The intentional mislabeling of products derived from endangered species as legally tradable items raises concerns over the efficacy of the current CITES monitoring requirements to protect vulnerable shark populations. In their letter, Sims & Frost outline the urgent need for CITES signatory nations to invest in the development of comprehensive genetic testing methods, which would allow for rapid species identification and provide additional deterrents to illegal harvesting and trade.

Fresh shark fins drying on sidewalk in Hong Kong. Photo © Nicholas Wang CC
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Project Update

MMTT pre-conference Workshop at OceanObs’19

OceanObs’19 is a conference held once every ten years, with a mission to progress ocean observing networks and to chart innovative solutions to society’s growing needs for ocean information in the coming decade. At this years’ event, hosted in Hawaii in mid-September, Dr Ana Sequeira (MMMAP core researcher) will be giving a plenary presentation and hosting the Marine Megafauna Task Team (MMTT) pre-conference workshop (14-15 September 2019).

The MMTT workshop (see poster below), organised by a number of MMMAP Core Researchers, will focus on coordinating the integration of marine megafauna data into ocean observing systems. Expressions of interest are currently open to attend this workshop but places are limited, so submit yours to lauren.peel@research.uwa.edu.au before 18 August to secure your attendance.

We look forward to seeing you in Hawaii!

Project Update

Nowhere to hide: pelagic sharks under threat from industrialised fishing

In a world-first study led by the Global Shark Movement Project and published this month in Nature, satellite tracking technologies have revealed the extensive pressure that industrialised fishing fleets impose on pelagic shark populations around the world. The study included a team of over 150 scientists, coordinated by Professor David Sims, and led by Dr Nuno Queiroz, Dr Nick Humphries and also Dr Ana Sequeira (MMMAP leader). Together, the team combined tracks from 1,681 large pelagic sharks of 23 species and examined the level of overlap that they displayed with fishing vessels that were monitored via a safety and anti-collision system.

Blue shark caught by Atlantic longline.
Photo © Marine Biological Association (UK)

In an average month, 24% of the space use by sharks fell under the footprint of pelagic longline fisheries. Monthly overlap was even greater for commercially targeted species, such as North Atlantic blue (76%) and shortfin mako sharks (62%), and for protected species, such as great white sharks and porbeagle sharks (~64%).

These findings highlight the lack of spatial refuges available to pelagic sharks in the high seas, and emphasise the urgent need to develop scientifically-informed management strategies, such as Marine Protected Areas, to conserve their populations.

This is a great example of the power of collaborative studies to address global conservation issues and involved many MMMAP researchers as co-authors.

Project Update

Marine megafauna as ocean observers

Southern Elephant Seal (Mirounga leonina) (young) in South Georgia.
Photo – Serge Ouachée (Butterfly Austral) CC

In the bio-logging decade, advances in tagging technology are allowing researchers to examine the fine– and broad-scale animal movements in the marine environment like never before. Alongside recording valuable biological data, deployed tags are also able to sample the physical environment surrounding each individual as they travel; providing insights into both the drivers underlying patterns of animal movement, and of the status of oceanographic systems as a whole.

A recent review published in Frontiers in Marine Science, led by Professor Robert Harcourt and Dr Ana Sequeira (MMMAP Core Researchers) with a large number of colleagues, describes the value of tagged marine megafauna acting as “autonomous sampling platforms” throughout our oceans. The capacity of these animals to provide measures from a suite of essential ocean variables (known as EOVs) to global oceanographic observation systems is then discussed. It is expected that the increased spatial and temporal coverage provided by animal-borne tags will improve the monitoring of the Earth’s oceans moving into the future.

This publication is part of a series of Community White Papers solicited as part of the upcoming OceanObs’19 conference, taking place in Hawaii in September this year.

 

Project Update

Tracing the path of ocean observations in Australia

Established in 2006, Australia’s Integrated Marine Observing System (IMOS) endeavors to deliver national-scale ocean observations to the marine and climate science community. Whether provided in near real-time, or stored for ‘search, subset and download’ at https://portal.aodn.org.au/, the availability and discovery of collected data are paramount to the IMOS strategy and continuous efforts are made to ensure that data can be viewed and accessed by all who are interested.

Photo – Brayden Hsu

In a recent publication in Marine and Freshwater Research, Lara-Lopez and colleagues outline the steps that have been taken by IMOS to improve user access to the suite of available environmental and biological data. These include the provision of map-based previews of data (IMOS – OceanCurrent; http://oceancurrent.imos.org.au/), and the integration of analysis into observation programs (e.g. IMOS Animal Tracking Acoustic Telemetry facility). The authors also highlight the benefit of engaging multiple stakeholders with the IMOS workflow, and the improved ability to address major national and regional science priorities that such collaboration provides.

Project Update

Coastal sharks: interspecific interactions, movement patterns and habitat use

Juvenile black tip reef sharks cruise the shallows . Photo © Kris-Michael Krister (CC)

Coastal aggregations of sharks represent a unique opportunity to examine how the movement and foraging strategies of predators may vary in the presence of potential competitors. In a recent publication in Marine Biology, Dr Michelle Heupel (MMMAP core researcher) and colleagues leveraged a large, existing set of acoustic telemetry data to investigate the interactions, movement patterns and habitat use of six shark species in a coastal bay in north-eastern Australia that acts as a nursery area for these animals.

The extent of spatial overlap recorded in core-use areas varied greatly between shark species, but remained consistently low (< 30 %), meaning that spatial partitioning may aid in reducing interspecific competition. Where high levels of overlap of activity space were noted (up to 60%), stable isotope data showed differences in the foraging behaviour of the sharks involved. Dietary partitioning was hypothesised to concurrently reduce levels of competition and support the co-occurrence of sharks species at the study site.

Taken together, the findings of this study highlight the complexity of interspecific interactions among predators in communal nursery areas.

Project Update

The importance of sample size in marine megafauna tagging studies

An albatross glides over the ocean

So, you’re about to start tracking some marine megafauna. How many tags do you need to deploy? Not sure?
Well, now you’re in luck!

A new review by Dr Ana Sequeira and colleagues, published this month in Ecological Applications, provides the framework for researchers to answer this important question. By considering the scientific outcomes of previous studies relative to the number of tags that were deployed, as well as the ethical, logistical and technical components of such projects, Sequeira et al (2019) succinctly outline the questions that can be answered by tagging programs of various sizes.

Whether your proposed research aims to ‘innovate and discover’ (N ≤ 10 tags), to ‘confirm and consolidate’ findings (10 < N ≤ 100 tags), or provide a more ”synthetic, overarching and inter-disciplinary view’ of animal movement (N >> 100 tags), this review provides an invaluable insight into how to maximise the impact of each tag deployment in the decade of biologging.