Marine mammals in the Northeast Atlantic ecosystems

Dr. Gísli A. Víkingsson Head of whale research Marine and Freshwater Research institute Reykjavík, Iceland EUfishmeal Conference 29.8.2019 Area NE Atlantic Cetaceans in the Northeast Atlantic

• Total 30 species • Information on abundance and diet (food) limited for most species • 18 species considered here • Numbers are approximated due to data limitations Abundance and trends in the Northeast Atlantic (east of Greenland)Est Species Abundance Trend Biomass (Ktons) Diet Blue whale 3,000+ Increasing 210 Krill 70,000 Increasing 2100 Krill, • Total Biomass 6 million tons Sei whale 15,000+ ? 300 Krill, pelagic fish 130,000 Stable 650 Fish, krill • Species not included: North Humpback whale 12,000 Increasing 384 Pelagic fish, krill Atlantic Right whale, Bowhead Sperm whale 50,000?? ? 1700 Squid, fish Narwhal 6,000? ? 6 Fish, squid, shrimp whale, Dwarf sperm whale, Pygmy Beluga 5,000? ? 5 Fish, (molluscs) sperm whale, Cuvier‘s beaked N-Bottlenose whale 20.000+ ? 0.1 Cephalopods Killer whale 10,000 ? Herring, mammals, fish whale, Blainville's Beaked Whale, 20 Sowerby's Beaked Whale, Gervais' 600,000 Stable 480 Cephalopods (fish) White-beaked dolphin 250,000 ? 56.25 Fish Beaked Whale, True's Beaked White sided dolphin 250,000 ? 47.5 Pelagic fish) Whale, False killer whale, Pygmy Bottlenosed dolphin 50,000+ ? 15 Fish, squid Common dolphin 350,000+ ? 35 Pelagic fish, squid killer whale. Striped dolphin 500,000 ? 50 Pelagic fish, squid Risso‘s dolphin 11,000+ ? 3.85 Squid Harbour porpoise 450,000 ? 18 Fish, (squid)

Estimated diet and biomass of 18 cetacean species 2500

2000 Biomass of Northeast 1500

Atlantic large 1000 whales (thousands of 500 tons) 0 Fin whale Common minke whale Number (thousands) in Icelandic coastal areas Common minke whales 1987-2016 Humpback whale SCANS III survey 2016 Abundance – Population size Information needed for Body size → Biomass evaluating Migration → Residence time role as Feeding rates predators in Diet composition the ecosystem Trophic interactions → Ecosystem modelling Total consumption (blue) and fish consumption (red)

Harbour porpoise Risso‘s dolphin Consumption Striped dolphin Common dolphin by Cetaceans Bottlenosed dolphin Total consumption 45 White sided dolphin White-beaked dolphin million tons. Thereof 15 in the NE Pilot whale Killer whale million tons of fish Atlantic N-Bottlenose whale Beluga Narwhal Sperm whale Humpback whale Common minke whale Sei whale Fin whale Blue whale

0 2 4 6 8 10 12

Fish cons Million tons Fish consumption by cetaceans relative to fishery yield.

Cetaceans EU Total catch Norway Iceland

What can we expect in the future ? 1,0 Minke whale

0,8 Fin whale

0,6 “Ideal size” 60-72% N

Blue whale ?

0,4 0,2 ?

Right whale 0,0

0 20406080100

tími Changed distribution of many species

• Ling • Blue whiting

• Cusk • Herring

• Blue ling • Mackerel

• Capelin • Anglerfish

Teikningar: Jón Baldur Hlíðberg Summer distribution of mackerel2004, 2009 and 2018

Makrell 2004

Makrell 2009 R 74° u s s is k s e k to r Smutt- Fiskerivernsonen hullet Russlands Fiskeri- ved Svalbard 72° økonomiske sonen ved Grå- sone Øst-Grønland sonen

Fiskerisonen ved 70° Jan Mayen

Norsk økonomisk sone Smutthavet 68°

Islandsk sone Færøysonen 66°

EU-sonen Svensk sone 64° Dansk sone Tysk sone 62° Neder- landsk sone 60°

58°

24° 16° 8° 0° 8° 16° Distribution and migration of capelin

Before 2000 after 2000 2016 -

Green shade: Feeding areas (adult) Blue shade: Distribution of juvenile capelin Green arrows: Feeding migration Blue arrows: Migration from feeding grounds Red arrows: Spawning migrations Icelandic capelin catches since 1980 Predation on capelin:

• A key species both for fisheries and marine predators (fish, birds and mammals). • Total predation in Icelandic waters estimated as 2-3 million tons in the 1990’s • New catch rule takes account of fish predation between stock assessment and fishery season. • Whale predation has increased and will likely lead to decreased quotas. Pinnipeds (seals)

Consumption (million tons) by Consumption by three species of cetaceans and pinnipeds pinnipeds in the Northeast Atlantic in the NE Atlantic 50 8 45 7 40 6 35 30 5 25 4 20 3 15 10 2 5 1 0 Seals total Cetacean total 0 Grey seal Harp seal Harbour seal North Atlantic whale stocks were heavily depleted between 1860 and 1960

Many stocks have been recovering in recent decades and may continue to increase.

Today cetaceans constitute an important part of many NA ecosystems, with total fish consumption significantly larger Conclusions than the total fishery yield.

More research required to evaluate and quantify potential competition between marine mammals and fisheries

Global warming is adding to the complexity of this evaluation Thank you for your attention Whales as predators Consumption, global perspective

300

Fisheries 250 Cetaceans

200

150

100

50

0 Crustacea Cephalopoda Pisces Total

Based mainly on Tamura 2003 Status of populations

Source IUCN 2018 Hvalatalningar í loðnuleiðangri haustið 2016

Langreyður Hnúfubakur Gróft mat á daglegu áti hvala miðað við talningar á loðnuslóð 2015

Hnúfubakur– fjöldi hvala Langreyður –fjöldi ~5,000 ~ 7,000 • Áætlað magn fæðu (allir • Áætlað magn fæðu (allir fæðuhópar) í tonnum á fæðuhópar) í tonnum á dag - 3,100 - 7,800 dag -2,600 – 6,600 Hversu lengi ? Ferðir nokkurra merktra 21. Oct 2010 hnúfubaka

1 – 13 February 2009

20 Nov - 5 Dec 2014

28 Jan – 6 Feb 2010 13-20 January 2010