This month we are diving into a group that I have had a particular fascination with – kelp. Kelp are the foundations of temperate reefs in our shallower waters, and they are home to countless different species. A patch of this brown seaweed can support whole communities; lobsters, crabs, fish, shark eggs wrapped around their stipes, or stems, and even supporting other seaweeds growing on the surface of them. We have a huge variety of seaweed species here in Ireland, and kelps are of special importance for their own unique reasons.

This month we are taking a look at one of our most frequent jellyfish visitors, the moon jellyfish. Moon jellies are the most common jellyfish found in Irish waters. These glowing ethereal creatures can most commonly be seen on dives all around the coast between April and September.

I will talk about their classification, how to identify them, how they reproduce, and how they hunt, to hopefully answer some of your burning questions about this species.

The Dublin Bay seals are arguably one of the more fun species to encounter on a dive in Dublin Bay, especially if you’re around Dalkey Island when the younger grey seals are in the mood to play.

Dublin Bay is home to two seal species: the Grey Seal (Halichoerus gryphus) and the Common Harbour Seal (Phoca vitulina). The harbour seals tend to favour sandy beaches like Bull Island, but you might see them occasionally the south side of the bay as well. Generally, when we’re talking about the seals we scuba dive with, we are talking about the grey seal colony of Dalkey Island.

Are there dogfish in Dublin Bay?

Kate McGonagle

At first you would probably say yes, right? There’s lesser-spotted dogfish and large-spotted dogfish all over Dublin Bay - but the scientific answer is a little bit more complicated. Scientifically speaking, these are both species of catfish, and the lesser-spotted dogfish is now more appropriately named the small-spotted catshark, and the large-spotted dogfish, or bull huss, named the nursehound. We’re not 100% sure why they are called dogfish, but this naming difference tells us more than you might think, as the change in name paints a very different picture on the evolutionary tree that these sharks have branched from.