A pelagic baleen whale, adults measure up to 16 metres and can live for 65 years. Often confused with the fin whale, but lacks the asymmetrical colouration of the lower jaw and baleen of the latter. Bluish or very dark grey dorsally, Sei have a paler grey or whitish underside and throat grooves, numbering 32-62, and a whitish lower fringe to the baleen. Pectoral fins are dark on both sides. The slender dorsal fin is more erect than a fin whale’s and slightly further forward than other baleen whales. Sei whales can associate with Fin whales, but are sporadic visitors to UK shores. Calves are born at 4.4-4.8 metres in the winter months, becoming sexually mature at 6-8 years old. Usually travelling alone or in pairs, they feed by surface skimming plankton, copepods and euphausiids (krill), and small shoaling fish.
Sei whales are far ranging animals that visit the UK shore very infrequently, although may be seen during ferry crossings or far out to sea.
Due to their sheer size sei whales are generally not suitable for a refloat should they strand on the shore as they cannot be moved safely except by the tide. Their enormous weight will also begin crushing their internal organs, causing severe damage from which it is highly unlikely they will survive.
A whale, dolphin or porpoise stranded on the beach is obviously not a usual phenomenon. These animals do not beach themselves under normal circumstances, and they will require assistance. Please DO NOT return them to the sea as they may need treatment and or a period of recovery before they are fit enough to swim strongly.
BDMLR RESCUE HOTLINE:
01825 765546 (24hr)
RSPCA hotline (England & Wales): 0300 1234 999
SSPCA hotline (Scotland): 03000 999 999
You will receive further advice over the phone, but important things you can do to help are:
If you find a dead cetacean
The Cetacean Strandings Investigation Programme (CSIP) collects a wide range of data on each stranding found on UK shores. If you discover a dead animal, please contact the CSIP hotline and give a description of the following where possible:
Digital images are extremely helpful to identify to species, as well as ascertaining whether the body may be suitable for post-mortem examination.
CSIP has produced a useful leaflet that can be downloaded by clicking here.
CSIP hotline: 0800 6520333. Callers are given a number of options to ensure they reach the correct department. You can also use this number to contact BDMLR as there is an option for live animal strandings that transfers directly to us.