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Recovery from What? Scarcity of right whales in North Atlantic Ocean today – a few hundred animals May have been only a few 10’s in early 1900’s Single.

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Presentation on theme: "Recovery from What? Scarcity of right whales in North Atlantic Ocean today – a few hundred animals May have been only a few 10’s in early 1900’s Single."— Presentation transcript:

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2 Recovery from What? Scarcity of right whales in North Atlantic Ocean today – a few hundred animals May have been only a few 10’s in early 1900’s Single primary cause: commercial whaling Ship strikes and gear entanglement became major issues in late 1900’s Before then, whaling was THE issue

3 Historical questions How many right whales were there in the North Atlantic? How were they distributed seasonally and spatially in the past? Where did they calve, breed, rear young, and feed? Was there more than one biological population? Trends through time – constant decline or episodes of recovery? How small was the population at its nadir?

4 Defining Recovery Goals Numbers Distribution Viability

5 Relevant Previous Studies Maury (1850s) – logbooks and unpublished reports by whalemen

6 Glover M. Allen (1916) – “The Whalebone Whales of New England”

7 Townsend (1935) – logbook data Schevill and Moore (1983) – Townsend’s “unmappe d” right whales Aguilar (1986) – Review of Basque whaling for right whales

8 Studies by Reeves & Colleagues Reeves and Mitchell (1986) – American pelagic whaling; published and unpublished sources Reeves and Mitchell (1986) – Long Island shore whaling

9 Reeves and Mitchell (1988) – Southeastern U.S. shore whaling Reeves, Breiwick, and Mitchell (1999) – Northeastern U.S. shore whaling

10 Recent and ongoing

11 Main Contributions thus far Identification and characterization of calving grounds Identification of Cape Farewell Ground (feeding)

12 Clues to other feeding grounds (“Maury smear,” Gulf of St. Lawrence)

13 Confirmation of coastal winter/spring occurrence off mid- Atlantic states (e.g., Delaware Bay, New Jersey, New York) Hypotheses concerning population structure

14 Plausibility for trends and low point

15 Big Unanswered Questions Basque whaling in Newfoundland, Labrador, Gulf of St. Lawrence 14,000-18,000 barrels of oil in some years — 283-364 right whales How many were there in: Early 1500’s Aguilar: 300-500 balaenids/yr from 1530-1610 Ratio of right whales to bowheads uncertain

16 American colonial shore whaling Amounts of oil and baleen imported to UK from New England, New York, and Pennsylvania, 1724-1734, greater than 1,128 right whales Early 1700’s

17 American shore and pelagic whaling Average of at least 50-60/decade killed off U.S. east coast, 1850-1890 About 20 killed in 1890’s; 10 between 1900-1910 Central and eastern North Atlantic: 28 taken in Iceland, 1889-1904; 11 in Faroe Islands, 1892-1922; 118 in British Isles, 1906-1923 = ca. 160 in 35 years Late 1800’s - early 1900’s

18 Shifting Baseline Problem What do we mean by “a lot” of right whales?

19 Question: Was the western population on the road to recovery by the 1970’s and 1980’s?

20 Likely Answer: Yes, as it seems unlikely that there were more than a few 10’s of individuals alive by ca. 1620-1930

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22 Other Questions: In what ways and to what extent has the environment (“carrying capacity”) changed for right whales since 1500? What role, if any, did extirpation of bowhead whales in the Strait of Belle Isle play?

23 Need for improved reconstruction of balaenid (right whale and bowhead) catch history in southeastern Canada

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