Marine Mammals

Introduction

Always a special sight, marine mammals are large and charismatic marine species.

Marine mammals can be grouped into cetaceans (a collective name for whales, dolphins and porpoises) and pinnipeds (seals). Here, we include the European otter in this section as an aquatic mammal which spends a significant proportion of its time feeding in the inshore marine environment.

Marine mammals all give birth to live young, but none show the prolific breeding habits that are found in many smaller terrestrial counterparts, with most giving birth usually to a single pup / calf approximately every 1 to 4 years. All marine mammals breathe air but can dive to considerable depths for long periods of time. Marine mammals are top predators, mostly eating fish in the water column or on the seabed. Many species of cetaceans use echolocation to locate food and communicate with each other and can be disturbed by manmade underwater noise.

Marine Mammal species in Wales

Compared to the 47 terrestrial mammal species, there are relatively few marine mammals which spend a considerable part of their life feeding and breeding in Welsh waters. Species which are likely to be seen are the grey seal, bottlenose dolphin, Risso’s dolphin, common dolphin, minke whale and harbour porpoise, and the rather more elusive European otter found at the coast. Other species may be regular visitors and pass through Welsh waters while travelling from one area to another or to feed at certain times of year – these include species such as the humpback whale. Occasionally very unusual vagrants are found in Wales which are outside of their normal range (e.g. walrus).

Wales supports nationally and internationally important populations of marine mammals. Cardigan Bay is one of the only places in the UK with a resident population of bottlenose dolphins Tursiops truncatus, with approximately 200-300 found in the area, peaking in September – October. Wales also has a significant number of harbour porpoise around its coasts, and these are protected through three large SACs.

Risso’s dolphin Grampus griseus is another large, often distinctively scarred, deep diving dolphin. This species is seasonally resident in the summer around Bardsey Island, off the Llŷn Peninsula, and can also be seen off north Anglesey; the dolphins can be seen close to shore and are thought to be feeding on squid.

The common dolphin Delphinus delphis is a smaller, acrobatic dolphin found offshore in the Celtic Deep and around Pembrokeshire and St Georges Channel, where they occur often in large pods.

The offshore Welsh islands of Skomer and Ramsey and north Pembrokeshire coast are particularly important places for Atlantic grey seals Halichoerus grypus, with about 5,000 estimated to inhabit the area. They can be seen hauled out on rocky and sandy shores and their white-coated pups are born in the autumn, often in sea caves. Wales represents about 2-3% of the annual UK pup production and are features of four MPAs in Wales. Wales also has a small number of the smaller common / harbour seals Phoca vitulina, but the species is thought not to breed in Wales and is therefore not a component of any Welsh protected site.

The European otter Lutra lutra is not restricted to marine environments but do use inshore marine areas for feeding. The population of otter in Wales is widespread but at low density and there are 3 marine SACs in Wales where otter is designated as a feature.

Marine mammal conservation

Marine mammals are heavily protected under a number of pieces of legislation.

Marine mammals on the Environment (Wales) Act Section 7 list

Species name	Species common name	Welsh species name
Balaenoptera acutorostrata	Minke whale	Morfil pigfain
Balaenoptera physalus	Fin whale	Morfil asgellog llwyd
Delphinus delphis	Common dolphin	Dolffin cyffredin
Globicephala melas	Long-finned pilot whale	Morfil pengrwn
Grampus griseus	Risso’s dolphin	Dolffin Risso
Hyperodon ampullatus	Northern bottlenose whale	Morfil trwyn potel
Lagenorhynchus acutus	Atlantic white-sided dolphin	Dolffin ystlyswyn
Lagenorhynchus albirostris	White-beaked dolphin	Dolffin pigwyn
Megaptera novaeangliae	Humpback whale	Morfil cefngrwm
Orcinus orca	Killer whale	Lleiddiad, orca
Phocoena phocoena	Harbour porpoise	Llamhidydd
Stenella coeruleoalba	Striped dolphin	Dolffin rhesog
Tursiops truncatus	Bottlenose dolphin	Dolffin trwyn potel
Ziphius cavirostris	Cuvier’s beaked whale	Morfil gylfinog Cuvier
Lutra lutra	Otter	Dyfrgi

There are 14 species of cetacean on the Environment (Wales) Act Section 7 list, plus the European otter. Seals are not included on the list. Many of these species are not frequently encountered but nevertheless still included under this Act.

Marine mammals are strongly protected under the Conservation of Habitats and Species Regulations 2017 (The Habitats Regulations). Supporting areas of their habitat must be protected, and in Wales, sites are designed for bottlenose dolphin, harbour porpoise, grey seal and European otter. There are 7 SACs in Wales which have marine mammals as a feature. All cetaceans and otter are also European Protected Species (EPS) are afforded strict protection wherever they occur.

Under the Wildlife and Countryside Act 1981 (as amended), it is illegal to intentionally or recklessly disturb, kill, keep or sell these species under various sections of the Act.

The Act also requires the notification of SSSIs for species and habitats of interest. There are 24 coastal and estuarine SSSIs in Wales with Atlantic grey seal, bottlenose dolphin or European otter as a notified and / or qualifying feature.

In addition, seals in Wales are protected under the Conservation of Seals Act 1970. This provides for the protection, conservation and management of seals and prohibits killing, injuring or taking seals in Welsh Waters.

A comprehensive document exists which outlines marine vertebrate conservation legislation in Wales, although it should be noted that this predates Brexit and amendments to the Conservation of Seals Act 1970.

Marine Mammal Conservation projects

One particularly long standing project is the annual Atlantic grey seal pup count undertaken by NRW at Skomer Island since 1983. The number of pups and the timing of pupping is noted as well as photographing individuals to learn more about the population (size and trend) and to record signs of entanglement.

There are a number of citizen science projects in Wales which aim to engage the public in submitting sightings of marine mammals to build up a picture of their presence and distribution. The Welsh Sea Watchers project (run by Sea Watch Foundation) established in 2013, aims to establish a network of dedicated volunteers, volunteering their time to monitor, educate and raise awareness of the diversity of Welsh cetaceans. ‘Sea Watchers’ are tasked with setting up their own land based surveys and organising and getting involved in public awareness events.

The Cardigan Bay Marine Wildlife Centre (CBMWC) in New Quay, west Wales, carries out research work collecting data on the local bottlenose dolphin population and photo-identification. CBMWC also man the New Quay site for Ceredigion County Council’s ‘Dolphin Watch’ project. ‘Dolphin watch’ has also recently been taking place in Abersoch, Llŷn Peninsula and volunteers monitor compliance with the marine code.