Marine

A-lister Shraveena’s Anglerfish and Megrim Survey Weblog


My title is Shraveena Ventakesh and I’m presently doing my grasp thesis, at GMIT, on the feminine reproductive system of the Spiny Dogfish (Squalus acanthias).  I’m taking a look at how the system modifications at completely different phases of maturity to find out the features of particular tissues and their implications on inhabitants construction. I joined the 2nd leg of the Irish Anglerfish and Megrim survey, by way of the SMART Coaching Via Analysis Surveys Scheme (TTRS), so I may study extra about commercially essential species of fish, acquire expertise working at sea and acquire extra samples for my challenge. 

Being on the B group

I boarded the RV Celtic Explorer in Cork on the twenty fourth of February, with emotions of pleasure and nervousness. The vessel departed Cork at round 8 PM, anticipating tough climate. The scientists and college students had been known as in for a gathering and had been cut up into two groups, one working the 4 PM to 4 AM shift (‘the A group’) and the opposite working the 4 AM to 4 PM shift (‘the B group’). I used to be on the B group, the extra lucky of the 2. We had been at all times awake when the pancakes had been being made. 
The climate at the beginning of the expedition didn’t look nice. An enormous incoming storm pressured us to hunt shelter close to land. We needed to sit idly and be affected person, although we can not actually complain about that as a result of we had good meals, nice firm, a tremendous view and a few attention-grabbing motion pictures to look at. We additionally managed to catch a few Rugby matches, however the climate improved simply once I started to grasp and benefit from the recreation. 

Bantry Bay with Hungry Hill, our shelter from the storm

Out the hole and off to work

The storm handed and we set to work. We fished at completely different stations, at completely different depths. The fish caught within the nets had been introduced into the moist lab on a conveyor belt. We stood alongside the belt, sorting the completely different species into packing containers, paying homage to a manufacturing line in a manufacturing unit and simply as environment friendly. As soon as all of the fish had been sorted, the packing containers had been weighed and given labels by the deckmaster. The labels contained data just like the sampling station quantity, the species code and the intercourse.  All this information was entered into computer systems by scanning barcodes at workstations within the lab. The size of every particular person was additionally measured by scanning barcodes. For some species, like Anglerfish (Lophius piscatorius and Lophius budegassa), Megrim (Lepidorhombus whiffiagonis), Haddock (Melanogrammus aeglefinus), and so on., we additionally documented their intercourse and maturity and eliminated their otoliths. Otoliths are calcified components within the ears of fish that may assist decide the age of a person. They’re tedious to take away, particularly in smaller fish, however these components retailer a wealth of knowledge that’s essential in assessing the shares of those species. After all of the fish had been sorted, weighed and measured, and the workstations cleaned, we turned the lab right into a filleting station. Cleaned fillets of Hake, Mackerel, Haddock, Anglerfish, John Dory and extra had been bagged and frozen for consumption. These species, that had been resilient sufficient to outlive being pulled up in nets, had been saved in a tank and put again within the water after being measured and weighed. Some species like Boarfish (Capros aper) and the bits left after filleting had been thrown down a discard chute that led to the water, a lot to the delight of the Gannets that consistently circled the vessel.  Their favorite after all, was Mackerel (Scomber scombrus). Massive numbers of Gannets diving behind the vessel, because the nets had been being pulled up, was a certain signal that we had caught Mackerel. 

These otholiths are from  a Hake. Each species of bony fish has its personal signature otolith form

Chimeras and Monsters

The B group, having had the much less demanding shift, additionally carried out high quality checks, in between hauls, on the otoliths already collected. Our busiest and most attention-grabbing shift was the final one. The hauls had been from deep water stations, the place we bought to see unusual and completely different species that appeared to extra intently resemble creatures from a sci-fi film relatively than marine biota. We hauled up a number of specimens of Rabbitfish (Chimaera monstrosa). These peculiar organisms, shut kinfolk of sharks, rays and skates, had luminescent eyes as did another deepwater species. Elasmobranchs (sharks, rays and skates), to me, are probably the most fascinating group of marine organisms. Throughout this survey, I bought to see a number of completely different species like Black-Mouth Catsharks, Six-Gill Sharks, Birdbeak Dogfish, Torpedo Rays, Starry Rays, Cuckoo Rays and extra. I additionally bought to assist tag a Tope a Blue Skate and a Sandy Ray and launch them again into the ocean. 

Rob Jordan, GMIT postgraduate pupil tagging a tope

Nice Alternative

I had a terrific expertise on the RV Celtic Explorer. I loved working within the moist lab, an setting the place you get to see one thing new and attention-grabbing on daily basis. It was a fabulous alternative for me to study rather a lot in a brief period of time. I sit up for being on board once more and dealing within the moist lab, lined in fish scales and captivated by every part round me. 

Acknowledgements

I wish to thank Dave Stokes, Dave Tully and everybody else on the B group and the A group for introducing me to the fascinating world of fish biology and fisheries. I’d additionally wish to thank Dennis Rowan and his crew for ensuring every part went easily, regardless of the unlucky climate and Tony and Kevin for retaining us fed and pleased. I’m additionally very grateful to John Boyd and the Strategic Marine Alliance for Analysis and Coaching for giving me the chance to go on board the RV Celtic Explorer. 

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