Sea mammals and Shorewatch- a beginners perspective

By Rhiannon Jehu

Despite living in Shetland all my life, I know very little about the sea mammals that live so close to us. I decided to fix that and have written a few notes on what I have learned so far.

For many generations people have hunted whales. Commercial whaling started in the Middle Ages and by the 1750’s most Scottish ports were involved in the industry. Whales have provided us with oil for our lamps and meat for our stomachs. The hunting of cetaceans in Scotland stopped in the 1960’s and has reduced significantly worldwide. However, other challenges, such as increasing levels of pollution and underwater noise and by-catch from some fishing methods, has led to a crash in global whale, dolphin and porpoise (WD&P) populations.

Baleen whales (Mysticeti) who have baleen plates to filter their food; mostly plankton and small species of fish e.g. minke whales

(c) WDC

Toothed whales (Odonotoceti) which includes all species of dolphin and porpoise, such as the Risso’s dolphin and harbour porpoise. As the name suggests, these sub-order species all have teeth and often eat larger prey than the baleens. Most have cone-shaped teeth for grasping and holding their food. However, porpoises have flatter, spade-shaped teeth. Though porpoises and dolphins can look quite similar, porpoises are smaller and chunkier. This allows them to stay warm despite their smaller size and the cold water– short and round is easier to heat than long and lean. Also, porpoises can be heard to ‘puff’ through their blowhole while dolphins whistle through theirs.

(c) WDC
(c) WDC

One unique role that larger species of whale play is the ‘whale pump/poop pump’. Some species move between the low pressure of the surface and the high pressure of the depths when hunting. As they do this they cycle nutrients, taking it from the depths and carrying it to the surface where they release it. These mega-poops help to feed open ocean ecosystems.

Whales also create ecosystems in the ocean’s deepest darkest parts. Deep seas were once believed to be almost lifeless due to their extreme conditions; high pressure and eternal darkness. More recently explorers have discovered a wide range of strange and beautiful lifeforms. Many of these feed on marine ‘snow’ that falls from above. This is made up of the decaying bodies of plants and animals that are sinking to the ocean floor. A ‘whale fall’ is an extreme example of this. It occurs when a dead whale falls to the deep ocean floor. The body becomes a feeding ground and ecosystem for a multitude of other extreme survivors. One fall can support an ecosystem for years, even decades before becoming completely consumed.

To find out more about the role whales play in marine ecosystems, take a look at WDC’s Green Whale Campaign Website

The other week I attended a 1 day online training course run by Whale & Dolphin Conservation (WDC) so that I could take part in their ‘Shorewatch’ citizen science project here in Shetland. Shorewatch volunteers gather presence and absence data on cetaceans which is uploaded into the WDC database. This information is used for research purposes and to provide evidence of what is happening in marine ecosystems. For example, to advise our government on the most effective locations to put ‘Marine Protected Areas’ and on how effective these are. Shorewatch data and data currently being collected by the SCWG’s Shetland Porpoise Survey will be used locally by the Marine Spatial Planning team at Shetland UHI to fill knowledge gaps in the Shetland Islands Regional Marine Plan, to assisting marine management and planning decisions in the isles.

WDC Shorewatch

Shorewatch has been running since 2005 and has trained over 1000 volunteers, who carry out on average 9,000 surveys every year around Scotland. Each Shorewatch involves 10 minutes of intensive watching from a specific location.

We record:

  • The environmental conditions (sea state & visibility)
  • What boat traffic is on the water
  • What marine mammals we see
  • Any other interesting sightings.

For more info:

Shorewatch – Watching out for whales and dolphins in Scotland – WDC (wdcs.org)

I am discovering that WD&P’s are fascinating and awe inspiring. They also play important roles keeping our oceans fit and healthy – we are all dependent on each other. If the whales thrive, the seas thrive and if the seas thrive, we thrive. In Shetland we have a long history of connecting and valuing WD&P’s and we have easy access to them. There is so much more we can learn about individual species and their lifestyles. The more we know and understand them the better able we will be to live alongside them in harmony, to be able to be a small part of that process, is so exciting.


Shetland Porpoise Survey

Harbour Porpoise (Phocoena phocoena) are the smallest of the cetaceans to be spotted around Shetland. They are generally shy creatures and do not often approach boats but can be easily spotted from the shore. They are regularly spotted in Shetland waters in small groups and sometimes in large aggregations that are not seen in many other areas in the UK.

Despite them being commonly spotted we have limited records and do not fully understand seasonal variations in the areas they congregate and for what purpose. To fill this knowledge gap we are undertaking porpoise surveys in areas porpoise are commonly seen.

Copyright WDC/Charlie Phillips

In collaboration with Whale and Dolphin Conservation we have created two new Shorewatch sites, one overlooking Quendale Bay and one at South Nesting Bay. We will also be surveying from the already established Shorewatch site at Mousa Sound. The survey involves undertaking a watch and recording the presence of marine mammals. If porpoise are present further information can be collected on number of individuals and their behaviour. This data will be used by the NatureScot and the Shetland UHI to update the Regional Marine Plan and will assist in protecting areas that are important to these wonderful creatures.

To gather as much information as possible we need your help! Are you interested in marine mammals and have time to undertake a short watch from one of our survey sites? All equipment needed is in survey kits which are available at the survey sites in lockboxes 24hrs a day so watches can be done at your leisure. Don’t worry if you have limited experience as full training on marine mammal ID from experts Whale and Dolphin Conservation is provided! A great way to start your marine mammal spotting journey.

We are also looking for experienced drone pilots who would be willing to come out and drone over our survey areas when we know porpoise are present. This will allow us to gain more accurate counts of individuals, see any calves present and observe behaviours such as mating. If you would like to help, please get in touch.

Contact us at shetlandcommunitywildlife@outlook.com for more information or head to the Shorewatch website for more information on the Shorewatch project.