This summer I spent six weeks in Jersey, the largest Channel Island in the British Isles, conducting fieldwork for my MSc in Conservation with University College London. Supported by Blue Marine Foundation, and with help from Jersey Marine Resources and local fishermen, I collected data on commercial crustacean and mobile fish species to understand the effectiveness of two of Jersey’s Marine Protected Areas (MPAs): The Southeast protected zone and Les Minquiers. These MPAs, designated in 2010 and 2017 respectively, are No Mobile Gear Zones (NMGZs); in other words, closed to fishing practices such as dredging and trawling. In 2007, Les Minquiers MPA was also designated as a No Parlour Pot Zone (NPPZ), prohibiting the use of parlour pots (two-compartment lobster traps that restrict the escape of catch). These zones aim to protect both the diversity of species that live in these waters and the rich habitats that they depend on. The management measures also aim to recover commercial fish stocks to sustain the local fishing industry. It is, therefore, extremely important to understand whether these designations are achieving their objectives and how they compare to unprotected marine sites across Jersey.
My study involved two different methods: 1) Potting surveys using parlour pots to catch, measure (and release) commercial crustacean species; and 2) Baited Remote Underwater Video (BRUV) to record and analyse mobile fish. The commercial species studied were European lobster, European spider crab and brown crab; these fisheries are heavily targeted in Jersey and comprise of 70 percent (by financial value) of landings.
For the potting surveys, I firstly had to modify the gear I would be using. I wanted to collect data on both adult and juvenile crab and lobster populations, therefore the pot’s escape hatches needed to be closed and mesh added to their bases. Sounds simple, but I underestimated how long it would take to cut pieces of rusty mesh with a pair of garden pliers. Six hours later and I was ready to go, accompanied by an aching body that was slowly getting used to lifting extremely heavy pots!
Left to right: 30 modified parlour pots; The mesh and pliers used to modify the pots
Out to Sea
Week 2 and it was time to head out to sea. Working with a local fisherman, Gibby Gordon, on his boat, Insomnia, we travelled to our first site in the Southeast protected zone to deploy our three strings of ten pots on areas of rocky reef habitat. The Southeast is the largest MPA in Jersey and protects sensitive seabed habitats such as maerl beds and seagrass meadows, associated with high biodiversity and beneficial ecosystem service functions.
Undertaking my research on a commercial fishing vessel was a great opportunity to learn how crab and lobster are fished locally. Not only this, but it allowed me to understand how the livelihoods of those in Jersey are impacted by the reduction of fish stocks and gather different perspectives on how the fishing industry could be managed appropriately and sustainably.
Left to right: Gibby’s boat, Insomnia; The 30 parlour pots on board
After 48 hours, we lifted our pots and started our recording. Over the six days of visiting this site, we caught an impressive amount of spider crab, lobster, brown crab and velvet swimming crab, alongside catshark, cuttlefish and conger eels as by-catch. All crabs and lobsters were measured for size, sexed, weighed, and any presence of eggs, diseases or missing appendages were noted before being thrown back in. It was great working with Gibby, who shared his years of knowledge as to why certain patterns were occurring in our catch.
Left to right: European lobster; A cuttlefish found in our pots; A bucket of spider crab and brown crab
Down to the Minquiers
Day 6 at sea saw us head down to our second site at Les Minquiers, situated around 15 kilometres south of the island. The site is beautiful and remote, often known as a location to spot seals and dolphins, or explore a small, inhabited island at low tide. As before, we deployed our pots and collected them after 48 hours. This area is less heavily fished, and it was noticeable in our observations, finding a much greater abundance of lobster and larger brown crab at Les Minquiers. We also noticed that our catch was feistier at Les Minquiers than at the Southeast. This is an interesting finding, and we suspected it could be due to a change in water quality and oxygen levels, with lower oxygen levels reducing energy availability for activity and movement.
To our luck, most of my fieldwork was undertaken in the glorious sunshine, only facing winds of 37 and 27 knots on two days. Weather such as this can be challenging when lifting pots and bringing them aboard. It required ultimate teamwork, high spirits, and trust in each other to do the job properly. Altogether, we managed nine to ten days of the potting study, which felt like a huge achievement.
Left to right: Gibby and I fuelling up the boat; Measuring a spider crab on board Insomnia
Baited Remote Underwater Video (BRUV) work with Jersey Marine Resources
To undertake BRUVs as the second part of my study, I headed to sea on the Jersey Marine Resources boat, Norman Le Brocq, for five days to deploy 4 GoPro units inside the two MPAs and three unprotected sites. On camera, we caught a diverse array of marine life such as undulate rays, sand eels, black bream and a tope shark! It was great to be on board the Government vessel with a team of people working hard to protect Jersey’s marine environment.
Left and right: On board Norman Le Brocq, the Jersey Marine Resources vessel
Left to right: Conger eel on BRUV footage; Undulate ray on BRUV footage
A tope shark caught on video at the Paternosters reef on the west coast of Jersey
The results of this study have shown significantly greater abundances of lobster in the Minquiers than outside the MPA, and significantly greater brown crab abundances inside the MPAs than outside. This highlights the effectiveness of these MPAs in assisting commercial species recovery. However, as lobster stocks are still extremely low at the Southeast, and no significant differences were shown for mobile species between areas, this research suggests further management of Jersey’s waters is necessary to allow fish stocks and ecosystems to fully recover and thrive.
On my days off, I explored some of Jersey’s beautiful coastline. My days were spent snorkelling at Blue Marine’s new Snorkel trail at the Portelet Bay No-Take Zone (NTZ) and helping Jersey Marine Resources with wider potting and sea bream nesting surveys.
Left to right: Snorkel Portelet in Portelet Bay; On board Norman Le Brocq
Overall, my time in Jersey was an experience I will never forget. Being able to spend so much time at sea undertaking research on a topic I am extremely passionate about is something I have always dreamed of doing. I cannot thank Blue Marine enough for giving me the opportunity and the Marine Resources team for helping make my project a reality. A huge thank you to Gibby for taking up so much of his time to work with me, providing his boat and equipment, and for teaching me invaluable skills that I can take forward into my career.
Please watch this short video of my time in Jersey: