Methods

1. Frederick W. Wenzel1, Judith M. Allen2, Simon Berrow3, Tom Fernald2,Cornelis J. Hazevoet6,Beatrice Jann4, Conor Ryan3,Christian Schmidt7, Lisa Steiner8, Peter Stevick2, Pedro López Suárez5, and Padraig Whooley3 (1)National Marine Fisheries Service, Northeast Fisheries Science Center, 166 Water St., Woods Hole, MA 02543, USA. Email: Frederick.Wenzel@noaa.gov (2)College of the Atlantic, 105 Eden St., Bar Harbor, Maine 04609, USA. Email: jallen@coa.edu; tfernald@coa.edu; <PeterStevick@aol.com> (3)Irish Whale and Dolphin Group, Merchants Quay, Kilrush, Co. Clare, Ireland. Email: <simon.berrow@shannondolphins.ie>, padraigwhooley@eircom.net, <miolmor@gmail.com> (4)Swiss Whale Society, via Nolgio 3, CH-6900 Massagno, Switzerland. Email: beatricej@bluewin.ch; (5)NATURALIA, Sal Rei, Boa Vista, Cape Verde Islands. Email: curral_velho@hotmail.com; (6)Museu Nacional de História Natural, Rua da Escola Politécnica 58, 1250-102 Lisboa, Portugal. Email:< cjhazevoet@netcabo.pt> (7)Húsavík Whale Museum, Hafnarstett, PO Box 172, 640 Húsavík, Iceland <chschmi@uni-bremen.de>(8)Whale Watch Azores, 2 Estrada da Caldeira, Horta, Faial, Azores, Portugal <wwa2@yahoo.com> ABSTRACT: During the winter/spring months from 1990 to 2011, 15 cetacean surveys were conducted around the Cape Verde Islands off West Africa. The main target species was the humpback whale (Megaptera novaeangliae). Study periods varied from 14 to 90 d in duration. Study platforms included a 5-m inflatable boat, a 12-m catamaran, and/or 15-m sailing or motor vessels. Collectively, we obtained 118 individual humpback fluke photographs from this region. These fluke photographs have been compared to over 9,500 individual fluke photographs maintained in the North Atlantic Humpback Whale Catalogue. Based on photo-identification, humpbacks in the Cape Verde Islands have a relatively high inter-annual resight rate (> 25%) compared to other studied breeding locations in the West Indies. While this is partly due to increased probability of detection in a small population, this result nonetheless suggests strong site fidelity to this breeding ground. Nine photo-identified individuals from the Cape Verde Islands had been previously photographed on high-latitude feeding grounds. Four off Bear Island, Barents Sea, Norway; three off Iceland, and two have been resighted in the Azores in the spring, presumably enroute to their northern feeding grounds. These findings are consistent with the belief that the Cape Verde Islands represent a breeding ground for eastern North Atlantic humpback whales. Further research is required to clarify the importance of this small population and its breeding grounds. A delicate balance is required in which we monitor the increasing on-the-water tourism activities, with appropriate habitat preservation so that we may provide adequate protection to breeding humpbacks whales and their new born calves. • Introduction: History of North Atlantic Humpback Whale Catalogue (NAHWC) • In 1976, the first North Atlantic Humpback Whale fluke Catalogue (NAHWC) was created. Scientists discovered that the ventral side of the humpback flukes varied significantly in their black and white pigmentation patterns, allowing for individual identification. The NAHWC contains fluke photographs from as early as 1952, however most fluke photographs are from 1975 to present. Most Eastern North Atlantic humpback flukes are from 1992-2011. • The current fluke catalogue includes; YONAH (Years of the North Atlantic Humpback) 1992-93 and MONAH (MOre North Atlantic Humpbacks) collection of fluke photographs (2004-05) which currently provides the best estimate of the North Atlantic humpback whale population (Smith et al. 1999). The NAHWC is constantly being updated. All Cape Verde humpback fluke photographs have been submitted to the NAHWC Catalogue which is maintained at the College of the Atlantic, Bar Harbor, Maine, USA. The catalogue contains over 29,000 fluke photographs, (representing nearly 9,500 individual humpbacks) from 400+ contributors from 16+ countries on the North Atlantic Ocean. Current Knowledge on the Distribution, Migratory patterns and Relative Abundance of Humpback Whales (Megaptera novaeangliae) off the Cape Verde Islands, Eastern North Atlantic. Northwest Africa Table 2. Number of individual flukes captured and resighted over a number of years within the waters of the Cape Verde Islands. • Results -The CVI humpback whale population is small with a high re-sighting rate (>35.5% have been observed more than once). High site fidelity is important for understanding Eastern North Atlantic humpback whale behavior, genetic stock structure and migratory patterns. • Conclusion – The high resight and recaptured rate may be due to an individual’s (trap happy) behavior. We may assume that this small population (low hundreds) is what remains of the E. North Atlantic humpbackpopulation. However, the size of the CVI humpback population may be under estimated, as the waters of the Western CVI and NW Africa have not been adequately sampled. • There are matching fluke photographs between the CVI to Norway and Iceland, with no additional re-sightings over a 20 year span. More recent fluke photographs from Norway and Iceland are desired. • No humpback fluke photographic matches have been documented between the Caribbean waters and the Cape Verde Islands. • Male humpbacks have higher recapture rates than females on the breeding grounds due to low energy output (no reproductive costs, only migratory. Females have a higher energy cost due of migration, reproduction and nursing. Hence, mature females are unlikely to have annual migrations to the mating /calving grounds. • High number of mom/calf pairs are reported annually in the CVI. • Additional genetic sampling and analysis is required for investigating population structure are currently underway. Methods From 1990-2011, seasonal research expeditions to identify humpback whales from the waters of the Cape Verde Islands (CVI). Research seasons were from February to mid-May, from 3 weeks to 3 months in duration. Most on-water research was conducted from either 8 – 14 m sailboats, 5m inflatable RHIB’s or whale watching vessels. CVI 2009, 2010 w/calf and 2011 Figure 1. Northwest Africa and the Cape Verde Islands (CVI) The CVI are located 450 km West of Senegal. Azores 2006 (L. Steiner) Maio, CVI 2006 (IWDG) and Iceland Mn104 (C. Schmidt) Boa Vista 2011 & Mn111 Iceland (C. Schmidt) Bear Island 1984 - CVI 2004 and 2011 Iceland 1982 and CVI 1999 Bear Island 1994 – CVI 2008 and 2011 Figure 2. The CVI archipelago covers several hundred kilometers. Most humpback fluke photographs were collected near Boa Vista. Table 1. Number of individual flukes captured and recaptured per year within the waters of the Cape Verde Islands. Acknowledgments We wish to thank the hundreds of people who have contributed photographs to the NAHWC. Over the years, support for CVI research came from: Allied Whale, International Whaling Commission, Island Foundation (U.S.), Whale and Dolphin Conservation Society (UK), Cetacean Society International (USA), Heritage Council, BordIscaighMhara (Ireland), Karl Meyer Foundation and donations from anonymous IWDG members. To Phil Clapham, Phil Hammond, Randy Reeves, Steve Katona, Tim Smith, Per Palsboll, Finn Larsen, Tony Martin, Jon Lien, the General Directorate of Environment of Cape Verde (DGA) and the National Institute for Fisheries Development (INDP) and many others, we say, Thank you! Figure 3. North Atlantic Humpback whale migratory patterns as determined by resightings/recaptures of individuals by fluke photographs. Data maintained at the North Atlantic Humpback Whale Catalogue, Bar Harbor, Maine, USA.