Research Profile | Linda Mazza | MSc Marine Science & Climate Change

Cetacean-Vessel Interactions in the Strait of Gibraltar
3rd August 2023

Describe your MSc project?

My research project investigated the interactions between cetaceans and vessels in the Strait of Gibraltar during tuna fishing season, with the aim of highlighting any existing and potential causes for conflict. The Strait of Gibraltar is a unique marine environment and due to its strategic geographical location, underlying topography, and, therefore, very productive waters is both a maritime traffic and cetacean hotspot. As the second busiest vessel channel in the world, potential for human-wildlife conflict is high, with the seven commonly observed cetacean species being at risk of disturbance, entanglement, ship strikes and injuries.
Collisions are often – voluntary or involuntary – unnoticed and unreported; this affects traceability and, ultimately, conservation goals. Some mitigation efforts, such as the relocation of shipping traffic lanes or vessel speed reduction, have been discussed and/or introduced in other maritime/cetacean hotspots. In the Strait, some fishing, commercial and recreational activities, e.g. whale watching, are partially regulated; however, unfortunately, laws are often poorly enforced or not adhered to, resulting in illegal fishing and/or inappropriate interactions with cetaceans. This dynamic may be exacerbated in the summer, with the start of recreational tuna fishing seasons, which add pressure to an already exploited environment.
In order to gain a deeper understanding of cetacean/vessel interactions, my research investigated the behaviour of both stakeholders towards each other, through a combination of desk-based research and field surveys. The findings showed that disturbance and ship strikes are a constant threat to cetaceans, and highlighted the urgent need for: 1) further research on the topic and more effective collision mitigation measures; 2) improved communication among all relevant stakeholders, to facilitate any lobbying attempts with regulatory bodies; and 3) wider awareness raising efforts, to highlight the significance of this issue in the study area, which often involves endangered or critically endangered cetacean species.

What type of research has it involved and what skills have you learned?

The project had a desk-based and a field component; a review of scientific and grey literature was complemented by observations from a platform of opportunity, a whale watching vessel. The literature review included detailed scrutiny of over 100 papers, spanning from journal articles, NGO reports, as well as PhD and Master’s theses.

The aim was to carry out a comparative analysis with other collision hotspots worldwide, thereby identifying knowledge gaps and potential for improved conservation efforts in the study area. The analysis looked at factors, such as cetacean species and vessel types mostly involved in collisions/near-misses, cetacean protection legislation and existing or desired mitigation measures.

Field surveys involved collection of data, such as cetacean species/vessel type, abundance, behaviour, as well as environmental factors. All data were subsequently analysed using both univariate and multivariate statistics, to understand the cetacean/vessel relationship before, during and after tuna season, and highlight any collision risk.

The two research components allowed me to improve my Excel, literature review and scientific writing skills, whilst also learning marine mammal observation techniques and new methods of statistical analysis. Finally, being able to visually present findings in a concise yet accurate manner was another invaluable skill acquired throughout the project.

Were there any partners/stakeholders on your project?

The field component of the research was carried out in partnership with the Foundation for Information and Research on Marine Mammals (Firmm), which operates from Tarifa, Spain. Firmm kindly hosted me onboard their whale watching vessel, to allow me to conduct all observations; their invaluable, in-kind support and the crew’s company and knowledge played a key role to the success of the project.

Why should the public know about this topic?

Cetacean protection is a well-highlighted topic within the marine conservation sector, due to the widespread interest of scientists and the general public in charismatic megafauna. The shipping and fishing industries, tourists, and local communities however often lack basic knowledge of marine mammals, their ecology and the daily threats they are exposed to, such as ship strikes. This research highlights the tangible risks that both commercial and recreational vessels pose to cetaceans in the Strait, as well as the lack of compliance to existing regulations, and the difficulty in implementing effective mitigation measures in various parts of the world. The need for improved and ongoing educational activities by local NGOs and whale watching companies becomes apparent; responsible eco-tourism and informed citizen scientists, tourists and boaters can all significantly contribute to cetacean conservation, either directly, through making responsible choices and adhering to regulations or, indirectly, by supporting NGOs and the scientific community, thereby facilitating policy changes.

What is the wider impact of your research?

This project has built on existing evidence of cetacean/ vessel interactions in the Strait of Gibraltar, and can therefore support current and future advocacy efforts towards more effective marine spatial planning and enforcement of regulations. A wide range of stakeholders may benefit from this research; local NGOs who, through solid cases for support, are better equipped in their awareness raising attempts; tourists and the local community, who are the main target of grassroots organisations; and the local government, whose enforcement policies could be improved in light of the research findings. Additional future investigations (e.g. PhDs) in the study area might also be encouraged, and would contribute to more robust datasets, based on which context-specific mitigation measures can be adopted. Furthermore, findings from the comparative analysis with collision hotspots worldwide might be used, by international NGOs, for lobbying purposes, and to further species-specific conservation measures in those geographical areas of major concern. Ultimately, cetaceans will hopefully be the longer-term beneficiaries of effective, long-lasting conservation efforts.

Comments from Head of School

Cetaceans are important consumers at the top of the food chain and are majestic, charismatic megafauna that capture everyone’s attention. With the increase in trade where 8 in every 10 goods are transported by sea, the potential for cetacean ship-strikes is very high, especially within the Straits of Gibraltar – one of the busiest maritime routes in the world.
 Linda’s research has brought together various disciplines such as marine ecology, marine policy and shone a light on the high potential for human-wildlife conflict in the form of cetacean-vessel interactions. The Straits of Gibraltar is not just an important maritime trade route but also a key biodiversity hotspot where seven cetacean species are found migrating and feeding (both transient and resident species) including Sperm whales, Fin whales, Killer Whales, Striped dolphins, Bottlenose dolphins, Common dolphins and Pilot whales. Only through comprehensive Marine Spatial Planning efforts and compliance from all relevant stakeholders can we achieve true conservation efforts for these iconic animals.
We would like to thank Firmm for hosting Linda during her research project and facilitating this important research.
Dr Awantha Dissanayake, Head of School (Marine & Environmental Sciences)
  • MSc

    Master in Marine Science & Climate Change

    Designed and delivered by expert academics and scientists, this full or part-time interdisciplinary programme blends theoretical study with practical, field-based work. You will cover specialist subject areas and gain the skills required to tackle the complex issues associated with the sustainable development of marine ecosystems.[...]

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