Marine

CV21019 Coastal pathways and connectivity for dangerous jellyfish species (CoCoJel)


A staff of scientists from College Faculty Cork led by Chief Scientist Dr. Damien Haberlin carried out every week lengthy survey on-board the RV Celtic Voyager to analyze the seasonal coastal present that circulates in an anti-clockwise course across the southwest coast of Eire. This present is named a pathway for advecting Dangerous Algal Blooms (HABs) alongside the coast, and it’s thought this similar present may advect dangerous jellyfish into the bays of southwest Eire. These dangerous jellyfish species can have main detrimental impacts on the salmon aquaculture manufacturing as they are often swept by the salmon cages and sting the gills of the fish resulting in lesions and attainable mortality occasions.

The goal of this survey was to characterize the coastal present alongside 4 transects and to pattern zooplankton each inside and outdoors of the present to find out if there are any variations among the many plankton communities. To do that we deployed a CTD, which is an instrument that measures the conductivity and temperature of seawater as it’s lowered down by the water column. Utilizing temperature and salinity knowledge, we are able to calculate the density of the totally different water lots and decide the placement of the coastal present. This was a lot trickier than it sounds and we had nice assist from Sheena Fennell and Dr Martin White of NUIGalway to assist us pinpoint the present’s location. 

Deployment of the CTD rosette.  

Part plot exhibiting the east-west element of geostrophic circulate at certainly one of our transects. The coastal present is positioned at 2.5 – 7.5 km alongside the part distance with a most circulate of -40 cm s-1.

As soon as we positioned the coastal present we then deployed the multinet plankton sampler at two stations on both aspect of the present after which 2 stations inside it. The multinet is comprised of 5 plankton nets (300 µm mesh dimension) that may pattern zooplankton at a variety of various depths. To do that we operated the web from a winch within the dry lab and sampled from 75 m depth to the floor at a price of 1 m s-1. At each 15 m depth interval we deployed a plankton internet.

 Deploying the multinet plankton sampler.   

Samples had been processed within the moist lab on-board and we may see clear variations in zooplankton discovered on the totally different depth intervals e.g. dinoflagellates had been most plentiful within the 15-30 m depth zone whereas siphonophores had been most plentiful within the 30-45 m depth zone. We additionally discovered that totally different zooplankton communities had been current on both aspect of the coastal present, for instance, there have been extra jellyfish within the oceanic waters whereas the shallower coastal waters had extra crustacean larvae (e.g. crab larvae). A way more detailed evaluation of the samples are wanted earlier than we are able to decide if the coastal present plankton group is totally different to the water lots that encompass it. Maria McGuinness and Hannah Brownlow will spend the following 12 months working up these samples as a part of their PhDs: ‘JellyJet’ which is supported by Science Basis Eire by MaREI (the SFI Centre for Local weather, Vitality and Marine) and ‘Jelly4Cast’ which is supported by the Irish Analysis Council by an Enterprise Partnership Scheme with MOWI Eire. Each college students are based mostly within the Faculty of BEES (Organic, Earth and Environmental Sciences) at UCC.

Pattern jars of zooplankton sampled at 15 m depth intervals. You’ll be able to see that the 4th pattern jar (collected 15-30 m depth) is way darker than the opposite pattern jars. It is because it was filled with the dinoflagellate Tripos muelleri.

We recognized various totally different gelatinous zooplankton species in our samples together with Pleurobrachia pileus, Agalma elegans, Nanomia bijuga, and Aglantha digitale. We additionally recognized some crustacean zooplankton often called zoea which might be the larval levels of lobsters and crabs.

Catch of zooplankton from the multinet on sieve. A number of gelatinous zooplankton could be very evident on sieve.  

Drone shot of the Celtic Voyager.

Total, the survey was a terrific success and we’re hopeful that this would be the first of many surveys of its form. An enormous thanks to the crew of the RV Celtic Voyager who had been incredible in enabling us to have such a profitable survey.

Crew Jelly! (From left: Dr Damien Haberlin, Hannah Brownlow, Maria McGuinness and Dr Tom Doyle)

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