Under the European Union (EU) Common Fisheries Policy (CFP) the Irish Naval Service undertake the role of maritime surveillance of fishing control according to sustainable management of the North Atlantic fisheries resource. The Fisheries Control are divided into 26 units of fisheries control monitored for activities and catch regulation and restriction.

Identification of beaked whales at sea can be difficult, especially of juvenile animals. Northern bottlenose whales are perhaps the most easily recognised due to their large size (adults can reach up to 9.8 m in length),robust body and prominent bulbous forehead and beak.They have a brown/olive colour and a prominent falcate dorsal fin located two-thirds of the way along the back (with adults often being mistaken for minke whales if the bulbous head is not seen).The pectoral fins are paddle shaped and sit into grooves on the flanks of the body. The data collected includes observations, relative abundance, search for and range of Beaked Whales recorded from marine mammals observations on board ships of opportunity between 2005 and 2011.

The fin whale is Irelands most common large baleen whale and grows to a maximum body length of 24 m in the north Atlantic. Body colour is grey with a white underside. The head is v-shaped with a prominent rostrum in front of the blowhole. Jaw-colour is asymmetrical with the right lower jaw being white in colour and the left being grey, this is diagnostic for the species. A pattern of light and dark grey chevrons is noticeable behind the head in good light conditions. The dorsal fin is prominent and located two-thirds of the way along the back. It is variable in shape, though typically falcate or triangular. The species produces a tall columnar blow up to 6 m high which is very noticeable. The blow can sometimes appear angled if the animal blows while surfacing from depth. This species almost never flukes or breaches in Irish waters. Lunge feeding at the surface is sometimes seen off the south coast. The data collected includes observations, relative abundance, search for and range of Fin Whale (Balaenoptera physalus) recorded from marine mammals observations on board ships of opportunity between 2005 and 2011.

Adult humpbacks range from 11-16 m in length, with females being slightly larger than males. The head is broad with a series of fleshy knobs on rostrum (and sometimes on the lower jaw), called tubercles. Body colour is black with white on the throat and belly. The pectoral fins are extremely long (one-third of the body length) with scalloped leading edges. They are typically white in colour but may have a dark upper surface, with white beneath.The tail fluke typically has a dark upper surface with white beneath, however the under-surface can be dark in some individuals. The scarring, colour pattern and shape of each tail fluke is unique and provides for identification and tracking of individuals. The dorsal fin is small with a broad base, raised hump in front and "knuckles" behind. The blow is typically low and bushy and has a distinct V-shape when viewed from directly behind or in front of the animal. The data collected includes observations, relative abundance, search for and range of Humpback Whale (Megaptera novaeangliae) recorded from marine mammals observations on board ships of opportunity between 2005 and 2011.

Striped dolphins have a maximum body length of 2.6 m.They are a sleek dolphin species with a slender beak,similar in shape to common dolphin but slightly smaller.A falcate dorsal fin (dark grey in colour) is located half-way along the back. The body coloration consists of a dark grey cape extending from the beak to behind the dorsal fin. The flanks are a lighter grey, leading to pink-white undersides.A thin dark stripe runs from the eye to the anus (between the grey and white areas), while a broad dark band runs from the cape, just below the dorsal fin and tapers to a point on the flanks above the pectoral fins. The striped dolphin is a fast active swimmer which sometimes bow-rides, but not as frequently as the common dolphin, which it resembles in body size and shape. The data collected includes observations, relative abundance, search for and range of Striped Dolphin (Stenella coeruleoalba) recorded from marine mammals observations on board ships of opportunity between 2005 and 2011.

Common dolphins are Irelands most widespread and abundant dolphin species.They have an average body length: of 1.7 – 2.6 m.The beak, and back are dark brown to black, and the underbelly is white. The front flank patches are yellow and the rear flanks and the sides of the tailstock are streaked light grey. These features give a distinctive hourglass pattern on the sides, below the dorsal fin.The eye is surrounded by black, and a narrow stripe runs forward to the melon.Another dark stripe runs from beak to flipper and several beak-to-anus stripes may also be visible. A falcate dorsal fin is located mid-way along the back.The general body shape is sleek with the head having a prominent black beak. Common dolphins often approach vessels to bow ride and frequently breach clear of the water. Melanism is sometimes seen in this species, with elanistic animals lacking yellow pigmentation, which is replaced with black. The data collected includes observations, relative abundance, search for and range of Common Dolphin (Delphinus delphis) recorded from marine mammals observations on board ships of opportunity between 2005 and 2011.