The NEIFCA Environmental & Offshore teams have been hard at work again this year deploying and retrieving the 40 lobster settlement collectors at locations spanning Withernsea to Teesside. From last year biological samples revealed a number of rockling and butterfish which are predators of early benthic phase (EBP) lobsters. There were also a high abundance of porcelain crab and squat lobsters, species which would compete with EBP lobsters for refuge.
Pic 1. Microscopic view while processing samples at Hull University's Marine Lab looking for any small organisms.
Therefore, the design was adapted slightly this year to address these concerns by adding 5 airbricks amongst the cobbles within the settlement collector to offer greater refuge, as well as the addition of plastic mesh to the lid of the settlement collectors to prevent fish species that would likely predate on EBP lobsters from entering.
Pic 2. Sorting through the benthic invertebrates found within the ELSI Settlement cage to gather biological sample for taxonomic ID.
All 40 settlement collectors were deployed during May 2023 and left to become colonised by benthic communities throughout the summer with the aim of collecting more EBP lobsters. Operations commenced at the end of August/beginning of September to retrieve and process these settlement collectors. So far, 24 ELSI settlement collectors have been successfully retrieved. All cages are processed to extract biological samples which are then transferred to University of Hull’s Marine Lab for taxonomic identification.
Pic 3. Cobble from an ELSI Settlement cage covered in keel wormcasts and a featherstar.
Next Steps........NEIFCA will be coordinating a second operation during November to retrieve the remained 16 ELSI settlement collectors. Taxonomic identification of all biological samples is ongoing as well as reviewing data from the environmental data loggers that were deployed at each sampling site to monitor water temperature and salinity.
Pic 4. Hauling ELSI Settlement cages onboard NEG III
Please Note: If any commercial or recreational fishers come across an ELSI settlement collector entangled in their gear whilst at sea, please contact the NEIFCA office on: 01482 393515