IAP-24-117
Environmentally sustainable creel fisheries
Background and importance. Different marine areas globally face similar challenges regarding negative ecological effects associated with fishing activities, including from fisheries using passive or static gears such as trap gear. Trap gear fisheries (e.g., creels) are often referred to as sustainable compared to other fishing methods associated with lower use of fuel and bottom contact and habitat damage compared to some active fishing gear types as trawls [1]. However, passive gears are often specifically associated with some other challenges (e.g. [2]).
These challenges include impacts on marine biodiversity through bycatch of unwanted species or juvenile individuals (see, for example, [3]) and pollution. Specifically, fisheries represent a considerable source of marine macro- and micro-plastic plastic pollution, release of toxic substances and other negative effects such as continuous capture of animals by derelict gear (ghost fishing). For example, Richardson et al. 2022 [4] estimated that 2% of all fishing gear, including 25 million pots and traps, are lost at sea each year. This poses significant risks for marine communities and ecosystems.
Furthermore, since the capture principle in trap gear such as creels, relies on the use of bait, this in some fisheries constitutes a challenge regarding relying on other commercial fisheries for bait and use of substantial amounts of bait to capture target animals, questioning fisheries sustainability [5, 6].
Further research needs to be addressed. The extent and magnitude of the above-mentioned challenges often differ between different fishing areas due to differences in environmental conditions, fishing effort, fishing gear type and main target and bycatch species. Even though these topics are often mentioned in scientific literature (for example [6 – 9]), for specific fisheries and associated environments, several of these issues remains unresolved and often lacking sufficient scientific information. One of such fisheries is creel fisheries targeting crustaceans such as lobster (Homarus gammarus) and brown crab (Cancer pagurus). This type of fishery is widely used in the UK and faces the above-mentioned sustainability challenges. These research needs will be addressed by this PhD project.
Aims of this research project. This PhD project would focus on creel fisheries and approaches on how to improve creel fisheries for environmentally sustainable marine resource use. This key aim will be addressed by systematically assessing the key issues in typical creel fisheries targeting brown crab and lobster in Scotland. The scientific questions to be addressed during a 3.5-year PhD period would include assessing:
(Q1) ecological effects of these fisheries on the species compositions in these marine areas (with special focus on current bycatch rates and amounts of bait used),
(Q2) what technical improvements could have the potential to reduce bycatch rates of juvenile individuals in these creel fisheries,
(Q3) the approximate gear loss in this fishery and associated ghost fishing risk by derelict creels on target, non-target species as well as megafauna, and
(Q4) potential modifications in creel design (e.g. adaptations from other fisheries) which may lead to reductions in ghost fishing and thus improve environmental sustainability.
Expected impact. The research taking place in this PhD project will be related to potential applications in creel fisheries (e.g. through collaboration with Orkney Fisheries Association) to improve their sustainability. Furthermore, the candidate is expected to improve networking skills and share the results in international forums (e.g. ICES Working Group on Biology and Life History of Crabs or ICES-FAO Working Group on Fishing Technology and Fish Behaviour). Specifically, the results are expected to be used by the student for networking activities that will allow improvement of the student’s presentation skills and collaboration with relevant partners and other fisheries (nationally with stakeholders such as Orkney Fisheries Association and Scottish Creel Fishermen’s Federation, other institutes in UK and internationally, e.g., through networking activities during ICES-FAO conference). The results will also be used in further teaching activities.
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PhD project overview
Methodology
The practical approach planned during this PhD project would consist of the following activities.
First, the project would aim to estimate fisheries effect on the marine environment (Q1). The candidate will assess catch compositions focusing on observed bycatches of juvenile individuals and non-target species in creels in the existing fisheries, including data collection, monitoring the catches and using video recording analysis.
Furthermore, the candidate will use ghost fishing estimations (Q3) based on summarizing earlier results in different trap gear fisheries based on (i) systematic literature review studies on ghost fishing rates and (ii) local interviews estimating gear loss rates, and (iii) the duration of ghost fishing (e.g. when ghost fishing stops due to biofouling). This approach will follow and further develop the one outlined, for example, in Rijkure et al. 2024 [10].
The second set of practical work will be conducted in a laboratory where the candidate will assess the morphology of target species based on previously well-established methodology (e.g., [11]). These results would aim to provide an insight into technological changes needed for improvements based on video recordings during the first part of the experiments (Q2 and Q4).
The final stage would include pilot experiments assessing the new modifications such as specifically modified escape panels or plates using degradable components, limiting ghost fishing (Q2 and Q4).
The results are expected to provide content for at least three scientific publications that would correspond to three chapters of a PhD thesis that are based on scientific studies.
The overview of the approach for this PhD project is attached as a graph (please see the attachment “PhD project overview”).
Project Timeline
Year 1
Based on methodology described above, the key activities for Year 1 will include:
1.1. Necessary research training (approx. 10% of Year 1), e.g. through PGCert style programmes / opportunities.
1.2. Training for seagoing activities (approx. 5% of Year 1).
1.3. Ethics assessments and data management plan (approx. 5% of Year 1).
1.4. Work with the supervisory team and collaborators to define the spatial extent of the study and activities (approx. 10% of Year 1).
1.5. Conduct systematic review and write up results addressing sustainability challenges in selected creel fisheries (approx. 25% of Year 1).
1.6. Plan and address Q1 regarding identification of present challenges in selected creel fisheries, write the respective chapter (approx. 45% of Year 1).
Year 2
Based on methodology described above, the key activities for Year 2 will include:
2.1. Participate in PhD level fishing gear technology course (approx. 15% of Year 2).
2.2. Estimate creel loss rates and main drivers, including ghost fishing estimations and write up results for Q3 (approx. 45% of Year 2).
2.3. Plan and set up laboratory experiments (Q2) for study to be started in Year 3 (approx. 40% of Year 2).
Year 3
Based on methodology described above, the key activities for Year 3 will include:
3.1. Finish laboratory experiments addressing Q2 and write up results (approx. 45% of Year 3).
3.2. Prepare and test innovative designs in selected fishery; write up results (Q4) (approx. 50% of Year 3).
3.3. Present selected results at a scientific conference / meeting (approx. 5% of Year 3).
Year 3.5
Based on the methodology described above, the key activities for the last 6 months of this project will include focusing on finalising the PhD research work and focus on the main conclusions and discussions, submission of PhD and viva.
Training
& Skills
The candidate will be based primarily at Heriot-Watt University Orkney campus, with research stays, as agreed, at the University of Glasgow. Specific training events and research support will also take place at Heriot-Watt University Edinburgh campus.
The candidate will focus on the following training for field, laboratory work, data gathering and research:
1. Research training programmes and opportunities through the PGCert,
2. Safety training for sea-going research trips,
3. Safety training for working in a laboratory.
Further, the training and skills will include:
4. Training for performing research ethics assessments and how to devise a data management plan,
5. Statistics skills depending on the background of the candidate,
6. PhD level course in fishing gear technology research or equivalent,
7. Presentation skills,
8. Data synthesis and meta-analysis skills.
References & further reading
[1] Suuronen et al. (2012), doi: 10.1016/j.fishres.2011.12.009. [2] Gilman et al. (2021), doi: doi.org/10.1038/s41598-021-86123-3. [3] Lively & McKenzie (2023), doi: 10.1016/bs.amb.2023.07.001. [4] Richardson et al. (2022), doi: 10.1126/sciadv.abq0135 [5] Cerbule et al. (2023), doi: 10.1016/j.heliyon.2023.e13820. [6] Spoors et al. (2021), doi: 10.1016/j.fishres.2021.105974. [7] Mašanović et al. (2023), doi: 10.1139/cjfas-2022-0190. [8] Goodman et al. (2021), doi: 10.1016/j.marpolbul.2021.112766. [9] Cerbule et al. (2023), doi: 10.1016/j.marpolbul.2023.115249. [10] Rijkure et al. (2024), doi: 10.1016/j.marpol.2024.106187. [11] Herrmann et al. (2021), doi: https://doi.org/10.1016/j.ocecoaman.2020.105495.
