DOCSLIB.ORG

Growth Rates of Sea Turtles in Watamu, Kenya Earth & E-Nvironment 2: 29-53

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Growth Rates of Sea Turtles in Watamu, Kenya Earth & E-Nvironment 2: 29-53 Watson DM (2006) Growth rates of sea turtles in Watamu, Kenya Earth & E-nvironment 2: 29-53 Earth & E-nvironment 2: 29-53 University of Leeds Press Growth rates of sea turtles in Watamu, Kenya Douglas M. Watson School of Earth & Environment, University of Leeds, Leeds, W. Yorkshire LS2 9JT; Tel: 0113 3436461 Abstract Green Turtles (Chelonia mydas) are at the forefront of conservation efforts due to their protected status and this relies on increased knowledge and awareness about them and their characteristics, including growth, from around the world. In Watamu, Kenya on the Western Indian Ocean coastline a capture-mark-recapture (CMR) study was carried out over a period of several years to produce recapture interval data. Growth analysis from changes in length over time found rates are non-monotonic, similar to those observed in the Pacific Ocean and ranged for Green Turtles from 0.468-10.67cm/yr (95% confidence), mean 5.18cm/yr (s.d 2.83). These rates were more rapid than many locations worldwide, with both seasonal and annual variations in growth along with recapture numbers and time. Average growth rates are slightly higher than the second most common species in Watamu: Hawksbill Turtles (Eretmochelys imbricata), which also has protected status. There is evidence for rapid individual increases in size outside the 95% confidence growth rate boundaries. The human measurement error found in association with carapace measurement highlights one of a number of limitations with such research. These findings are fundamental to a greater understanding of lifecycle, growth and morphological changes in the Western Indian Ocean, with limited comparable data from the region. They also have important implications for the successful conservation of not only the species present in Watamu, but also sea turtles in general. ISSN 1744-2893 (Online) © University of Leeds 29 Watson DM (2006) Growth rates of sea turtles in Watamu, Kenya Earth & E-nvironment 2: 29-53 1 Introduction The existence of sea turtles on earth stretches back in history to the cretaceous period with them generally found on the coast lines of mid latitude countries where they periodically visit beaches to forage and nest. Increased pressure from fishing with more technologically developed methods and impacts from urbanisation has led to a decline in populations. Hence more recently this has resulted in them being at the forefront of conservation efforts to help restore this decline to their pre-exploitation levels. Life History research is imperative to inform management techniques aimed at aiding population recovery. A number of projects have strived to achieve this with respect to the Green Turtle (Chelonia mydas) which was recognized as being globally under threat in 1990 (National Research Council, 1990). It is now listed as endangered by the World Conservation Union (IUCN; Hilton-Taylor, 2000) with populations estimated to have declined by 37-61% over the last 141 years (Seminoff, 2002). Consequently a substantial time and effort has been put into further understanding the species with specific focus on the quantification of growth of Green and Hawksbill Turtles (Eretmochelys imbricata) under natural conditions, normally with the use of capture-mark-recapture (CMR) programmes. The Hawksbill Turtle’s status is Critically Endangered (IUCN; Baillie and Groombridge, 1996) with further research being now fundamental to its future. One such study has been undertaken in Watamu Kenya, where for the last 7 years the local Non-Governmental Organisation (NGO) Watamu Turtle Watch (WTW)/ Local Ocean Trust (LOT) has been working with local people to increase educational awareness and help conserve populations. Analysis from this location is imperative due to the limited quantification of growth rates in Western Indian Ocean sea turtles. The aim of this study was to investigate the growth of sea turtles, specifically Green Turtles, in Watamu Kenya, with the use of a mixed-longitudinal capture-mark-recapture scheme. To achieve this, the following objectives were set: • Analyse growth data for Green Turtles in Watamu to determine how rates vary throughout the lifecycle, and compare the rates to corresponding values found in locations worldwide. • Quantify the human measurement error associated with the longitudinal study and asses how much impact this has on the findings. • Identify any variations in annual recapture rate/growth and evaluate the success of the CMR programme. • Compare Green Turtles growth rates of to those of Hawksbill Turtles and attempt to estimate the age of the Green Turtles using a recognised growth function. 2 Literature review 2.1 Historical context The importance in this specific area of sea turtle research is that an understanding of growth and growth-pattern variation helps develop an understanding of potential rates of population decline and recovery (Zug et al., 2002). This can help lead to successful conservation measures like one seen in Hawaii where there has been a significant increase in numbers of Green Turtles following the implementation of strategies stretching back to the 1970’s (Balazs and Chaloupka, 2004a). Further evidence that this is not just simply natural multi-decadal variability comes from the fact that the initial number recovery coincided with the Endangered Species Act 1978 (Hays, 2004). This came centuries after the first conservation legislation in the world against the killing of sea turtles below a specific size, that originated from the Bermuda Assembly in 1620 (Bustard, 1972). Consequently it can be seen that there is a long term emphasis on sea turtle conservation which can only continue to gather momentum with increased knowledge of such species. 30 Watson DM (2006) Growth rates of sea turtles in Watamu, Kenya Earth & E-nvironment 2: 29-53 2.2 Study site Watamu is a small coastal fishing town found on the eastern coast of Kenya, East Africa. Situated around 20km south of Malindi, its coast is part of the wider Watamu/Malindi Marine Parks and Reserve (WMMPR) and has a separate designated Marine Park around the shoreline encompassing three bays. The town is small, friendly and consists of numerous houses, shops, stalls, hotels and amenities spread along the sea front. 2.3 Site context It has been recognized for years that there are excellent reefs and turtle populations present on the east coast of Kenya around Watamu and Malindi (Frazier, 1995). Consequently Watamu Turtle Watch (WTW) was formed in 1997 following years of work by local naturalist Barbara Simpson to help conserve the local marine ecosystem. WTW specifically focuses on research and conservation of a variety of sea turtle species that regularly forage and nest in the area. In 2002 WTW expanded and formed the Local Ocean Trust (LOT) with a broader emphasis help conserve the WMMPR. Other LOT activities include an environmental education program which includes an information centre in the town centre and scheduled events with schools and local groups. Activities include working with the local people to inform and educate them of the importance primarily the turtles have, and their impact on the greater ecosystem. Issues related to over fishing in inshore waters, the use of illegal fishing methods impacting on the turtle populations, pollution, marine destruction and uncontrolled development are being tackled in the area (WTW, 2006). The education programme is closely connected to a cash reward scheme where fishermen present their turtle catch for measurement, tagging and release with the reward greater for a larger older turtle. This allows over time a CMR scheme to be in effect compiling data about individual turtles. 2.4 Capture-Mark-Recapture (CMR) schemes Schmidt (1916, in Balazs, 1995) carried out the first recognized attempt to quantify growth and population in the Virgin Islands using the CMR technique; previously they had not been seriously attempted due to the challenges posed with actually capturing the immature turtles (Balazs, 1995). Presently the main challenges to these studies include the fact that sea turtles are relatively slow growing, resulting in long term labour and time investment and the likelihood of recapturing individuals is relatively poor due to the nature of their movements and migration routes (Bjorndal et al., 2001). However, when successfully carried out over a period of time results from CMR studies produce direct growth measurements which can be used to model population and age specific growth rates (Lutz and Musick, 1997). Unfortunately it is difficult to measure growth in the early size range (hatchlings) in the wild due to the high natural mortality (Bjorndal et al., 2001) and the prolonged time they spend at sea before returning to foraging grounds to grow to maturity (Musick and Limpus, 1997). The juvenile to nesting stages are where most recaptures take place. Furthermore anthropogenic impacts in terms of mortality of juveniles and adults (Bjorndal et al., 2001) for meat and trade compounds the already difficult task of measuring growth in wild reptiles. In order to carry out morphometric measurements and to mark the turtles they must be actually caught, with a number of techniques used in the past. Common methods include scoop nets, tangle nets, basking, (Balazs, 1995) and bullpen or pound nets (Balazs and Chaloupka, 2004b). Also hand capture from a skiff, land (Green, 1993) or small boats and snorkelling/scuba at night (Balazs et al., 1996; Balazs and Chaloupka, 2004a) has proven to be effective. Finally, capture methods can include using turtle rodeo (Limpus and Reed, 1985) which involves jumping on them from the bow of a boat after a pursuit. Recapturing individuals over time enables profiles to be built up of morphometric data including straight carapace length (SCL) or curved carapace length (CCL) along the midline of the carapace. Also straight carapace width (SCW) or curved carapace width (CCW) at the greatest 31 Watson DM (2006) Growth rates of sea turtles in Watamu, Kenya Earth & E-nvironment 2: 29-53 point of width (Balazs, 1995) are taken at first and subsequent recaptures (Lutz and Musick, 1997).
Load more

Recommended publications
  • The Impact of Watamu Marine National Park on Marine Biodiversity & Habitats
    The Impact of Watamu Marine National Park on Marine Biodiversity & Habitats A Conservation Research Project by A Rocha Kenya Robert Sluka, Benjamin Cowburn, Colin Jackson A Rocha Kenya, Watamu Ornithology Section, Zoology Dept, National Museums of Kenya, Nairobi — A Rocha Kenya Occasional Research Report #24 — August 2012 Impact of Watamu Marine National Park on Marine Biodiversity – A Rocha Kenya & KWS, 2012 Executive Summary The original project vision was “to study the impacts of Watamu Marine National Park (WMNP) on marine biodiversity, habitats, and animal behaviour through high level research and facilitate capacity building for East African marine research and volunteer-led marine conservation at Mwamba Field Study Centre, A Rocha Kenya, Watamu.” From the original proposal the main research goal was to collect baseline data that would provide a basis for identifying key research questions and areas of conservation concern within the National Park environment. During the 2011/2012 field season we were able to conduct three studies identified as important by Kenya Wildlife Service (KWS) who are the government institution managing the marine park: biodiversity of WMNP, Tourism Impacts on Coral Gardens, and Coral Recruitment studies. During these studies our taxonomic identification capacity grew to include fish and coral species found in WMNP and have focussed our attention on IUCN red list priority species for pursuing further data collection. In order to present at conferences and publish results in peer reviewed journals we are using data to produce two papers currently focusing on the results of the tourist study. We are working in a partnership with CORDIO to use our biodiversity data in another paper to be submitted in 2013.
    [Show full text]
  • Kenya Marine Mammal Network
    Kenya Marine Mammal Network NEWSLETTER ISSUE 2 JANUARY 2013 IN THIS ISSUE: Welcome to the second edition of the KMMN Newsletter! Sightings April- 2 September 2012 KMMN Photos 3 Synchronized 4 Humpback whale breaching off Shimoni, South coast, Kenya Whale Watch- ing Day 2012 In this second edition of the newsletter we will continue to provide the first consistent data on occurrence and abundance of marine mammals along the Kenyan coast collected by sport fishing vessels, diving clubs and NGOs. This project will help to define ar- Dolphin watch- 4 ing training eas of “High Importance” for marine mammals, improving our local under- courses standing of these species on a broader temporal scale. At the same time, this data is extremely important for the marine mammal conservation and management strate- Convention on 5 gies in Kenya and it may be used as a baseline for further studies. Biological Di- versity Re- gional Work- shop KMMN on the 6 media Watamu’s top 7 Humpback Bottlenose dolphin interacting with an octopus in Kisite Mpunguti Marine Protected Area Whale Report- ers The Kenya Marine Mammal Network project proponent GVI (Global Vision International), KMMN collabo- 8 partnering with Watamu Marine Association (WMA) and Kenya Association of Sea Anglers rators (KASA) and supported by Kenya Wildlife Service (KWS) and Kenya Marine Fisheries Re- search Institute (KMFRI) wants to wish all its whale reporters a Happy New Year 2013, filled with many adventures & great encounters! The Kenya Marine Mammal Network P A G E 2 Sightings April—September 2012 From April and September 2012, 144 sightings (Fig.
    [Show full text]
  • The Geomorphology of Southeast Kenya
    THE GEOMORPHOLOGY OF SOUTHEAST KENYA A. P. Oosterom STELLINGEN 1. Bij de vorming van de uitgestrekte planatievlakken in Oost-Kenia heeft marine en lacustrine abrasie een belangrijke rol gespeeld. Dit proefschrift. 2. De schaarste aan fossielen van hominiden in Oost-Afrika over de periode van ongeveer 500 000 tot 50 000 jaar BP is schijnbaar. 3. Voor de toepassing van geografische informatiesystemen op bedrijfsniveau in reliefrijke gebieden is het essentieel om programmatuur te ontwikkelen die identificatie van de geologische en geomorfologische positie van een gekozen punt mogelijk maakt. 4. De klink van het Basis- en het Hollandveen is er medeverantwoordelijk voor dat er in Nederland geen aanwijzingen worden gevonden voor hoge holocene zeestanden. 5. De geringschatting van het belang van onderwijs en onderzoek in de geologie en geomorfologie aan de Landbouwuniversiteit te Wageningen is een uiting van onwetenschappelijk doe-het-zelf-denken. 6. Zolang de programmatuur voor het opnemen, opslaan en opvragen van kaarteringsgegevens minder flexibel is dan een veldboekje staat het gebruik van handterminals en veldcomputers vernieuwing in de weg. 7. De betrouwbaarheidsgrens van 25 000 jaar voor de datering van organische carbqnaten met behulp van de 14C-methode is te hoog.. Dit proefschrift. 8. Het woord automatisering wekt onjuiste verwachtingen als het gaat om de invoering en het gebruik van computers. 9. Kerkelijke liedboeken behoren losbladig te zijn. 10. De stelligheid waarmee waarheden worden verdedigd is eerder een maat voor onkunde dan voor inzicht. Stellingen behorende bij het proefschrift: The Geomorphology of Southeast Kenya. A.P. Oosterom Wageningen, 20 april 1988 THE GEOMORPHOLOGY OF SOUTHEAST KENYA Promotoren: Dr.
    [Show full text]
  • Kilifi Secondary Data Review As at February 2014
    KILIFI SECONDARY DATA REVIEW AS AT FEBRUARY Kilifi County constitutes 2.9% of the national population ranked 2014 8/47. 58.3% of the population are male while 51.7% are female Table 1 Introduction The county shares 25.7% of the national urban population ranked 13/47 CRA 2011 This document is a baseline for humanitarian needs assessment in Malindi town is the largest urban population taking 11% of the Kilifi with an aim to provide information that would aid in decision county’s population,Kilifi 4%, Mtwapa 4%, Mariakani 2%, Watamu making. The information presented has been gathered through a 1%, Majengo 1%, Mazeras 1%, Magarini 1%, Njiabini 1%, Marereni 1 review of pre-crisis secondary data, studies and lessons learnt 1%, Kaloleni 1% reports. Available indicator information is by Sub County, county and It has a population density of 473.1 which is higher than the national (where there is no available sub-county/county information). national population density of 401.1 per square kilometer, with 88 people in every km 2 see Table 1 This desk review is to help in the process of assessment planning for humanitarian needs assessment. The rate of poverty (adult equivalent poverty head count) is 70.8% higher than the national rate of 45.9% and its ranked 39/472 Purpose of the Desk review The average household size in Kilifi is 5.6, 1.2 higher than the national household size of 4.4. Table 1. This desk review is not a comprehensive survey on food security, The population age distribution is as follows 0-4 years 47%, 15- livelihoods, WASH, protection e.t.c nor is it an inter-agency needs 34 33%, 35-64years 17% and over 65 years 4%3 assessment.
    [Show full text]
  • 01 Mombasa 001 Changamwe 132,692 16.00 0001 Port Reitz
    County No. County Name Constituency No. Constituency Name Constituency Population Constituency Area In Sq. Km (Approx.) County Assembly Ward No. County Assembly Ward Name County Assembly Ward Population (Approx.) County Assembly Ward Area In Sq. Km (Approx.) County Assembly Ward Description 01 Mombasa 001 Changamwe 132,692 16.00 0001 Port Reitz 31,720 4.00 Comprises Part of Port Reitz Sub–Location Mombasa County 0002 Kipevu 29,100 2.10 Comprises Part of Chaani Sublocation of Mombasa County. 0003 Airport 31,721 4.00 Comprises Part of Portreitz Sub–Location of Mombasa County 0004 Changamwe 11,013 3.80 Comprises Changamwe Sub–Location of Mombasa County 0005 Chaani 29,138 2.10 Comprises Part of Chaani Sub–Location of Mombasa County 01 Mombasa 002 Jomvu 117,487 29.00 0006 Jomvu Kuu 38,776 19.00 Comprises Jomvu Kuu Sub–Location of Mombasa County 0007 Miritini 25,934 3.80 Comprises Miritini Sub–Location of Mombasa County 0008 Mikindani 52,777 6.20 Comprises Kwa Shee and Birikani Sub–Locations of Mombasa County 01 Mombasa 003 Kisauni 194,065 88.70 0009 Mjambere 27,573 4.15 Comprises Part of Magongoni Sub–Location of Mombasa County 0010 Junda 39,432 7.50 Comprises Comprises Junda Sub–Location of Mombasa County 0011 Bamburi 24,918 12.30 Comprises Bamburi Sub–Location of Mombasa County 0012 Mwakirunge 8,929 42.40 Comprises Mwakirunge and Maunguja Sub–Location of Mombasa County 0013 Mtopanga 27,573 4.15 Comprises Part of Magongoni Sub–Location of Mombasa County Page 1 of 168 County No.
    [Show full text]
  • City-Wide Inclusive Sanitation Plan for Malindi, Watamu and the Surrounding Peri-Urban Areas
    CITY-WIDE INCLUSIVE SANITATION PLAN FOR MALINDI, WATAMU AND THE SURROUNDING PERI-URBAN AREAS 2020 FOREWORD Kilifi County Government aspiration is to have a clean, healthy, and productive county. In addition, everyone should enjoy the basic right to sanitation. This should be achieved through an approach that is inclusive of all residents and delivers safe management across the entire value chain. These aspirations can be realized through efficiently managed local government bodies, including Water Services Providers and Municipal Boards. With the amount of waste that is safely managed in MAWASCO’s service area being 25%, over 90% of hand dug wells being contaminated, and there being no waste treatment plant, there is need for concerted efforts to make right investment for sanitation services. Environmental tourism is a driving force of Malindi’s economy and we cannot risk having waste be unsafely managed and polluting our environment. To continue being a preferred tourism destination we should focus on the goals outlined in this plan: Goal 1 Achieve equitable and financially sustainable access to safely managed sanitation for all Goal 2 Ensure clarity in mandates and market Malindi as the cleanest coastal town Goal 3. Create jobs and build local capacities to have a thriving sanitation economy Achieving these goals requires collaboration and coordination. As primary shareholder of MAWASCO, I am committing and urging the the utility in collaboration with other departments to follow these strategies. We will meet regularly to check in on our progress. My department will extend the necessary support ranging from resource mobilization for infrastructure investment and allowing MAWASCO to operate at arm’s length including providing enabling environment for public private collaboration Lastly, I would like to acknowledge and appreciate the support extended to MAWASCO and the Municipal Board by HE.
    [Show full text]
  • Coral Reef Ecology and Biodiversity in Watamu Marine National Park, Kenya
    Coral Reef Ecology and Biodiversity in Watamu Marine National Park, Kenya A Rocha Kenya Conservation & Science Report by Benjamin Cowburn1, Robert D Sluka2 and Joy Smith3 1A Rocha Kenya and Oxford University, UK 2 A Rocha Kenya 3 Current address: University of Bremen, Marine Zoology Department, Bremen, Germany — Occasional Research Report #27 — January 2013 A ROCHA KENYA | P.O. BOX 383 | WATAMU 80202 [email protected] | WWW.AROCHA.ORG | TEL: +254 (0) 202 335 865 Abstract Watamu Marine National Park is a 10 km2 marine protected area located on the central coast of Kenya. The biodiversity and abundance of fish and corals was studied in order to assess IUCN Red List species presence in the park and gain an understanding of distribution among several of the main coral reef sites. Ten species of fish and one species of coral were found that are assessed as Vulnerable or Threatened and four species that are Data Deficient. The highest coral cover was seen at Uyombo with 31% and the lowest at Turtle Reef (15%) . In terms of coral community composition, Coral Gardens and Bennett’s Reef were dominated by massive Porites colonies, whereas Uyombo and Turtle Reef had a more balanced coral composition with notably more Acropora and Pocillopora. Both Bennett’s Reef/Coral Gardens and Uyombo reefs had a similar size class distribution of fish, the mode falling in the 10-20cm size class. Both reefs were also dominated by surgeonfish, wrasse and parrotfish. We recommend a focus for future research on elasmobranchs (sharks, rays, guitarfish) and other IUCN Red Listed species.
    [Show full text]
  • Evaluation Report
    EVALUATION REPORT Watamu Marine Protected Area Location: Kenyan Coast, Western Indian Ocean Blue Park Status: Nominated (2020), Evaluated (2021) MPAtlas.org ID: 68812840 Manager(s): Kenya Wildlife Service (KWS) MAPS 2 1. ELIGIBILITY CRITERIA 1.1 Biodiversity Value 4 1.2 Implementation 8 2. AWARD STATUS CRITERIA 2.1 Regulations 11 2.2 Design, Management, and Compliance 12 3. SYSTEM PRIORITIES 3.1 Ecosystem Representation 17 3.2 Ecological Spatial Connectivity 18 SUPPLEMENTAL INFORMATION: Evidence of MPA Effects 20 SUPPLEMENTAL INFORMATION: Additional species of 20 conservation concern MAPS Figure 1: Watamu Marine Protected Area includes Watamu Marine National Park (dark blue, indicating that it is fully protected), Watamu Marine National Reserve (light blue, indicating that it is highly protected), and half of Malindi-Watamu Marine National Reserve (light blue lined; it is also highly protected). Watamu Marine National Park is a no-take marine refuge which provides coral reefs and a variety of marine species with total protection from extractive exploitation. The adjacent Watamu Marine National Reserve protects the estuary known as Mida Creek and allows limited fishing. The Malindi-Watamu Marine National Reserve, located on the coastal side of Watamu Marine National Park, also allows limited fishing. See Section 2.1 for more information about the regulations of each zone. (Source: Kenya Wildlife Service, 2015) - 2 - Figure 2: Watamu National Marine Park (pink) sees high visitor use. The Watamu Marine Reserve (yellow) is a Medium Use Zone. The portion of the Malindi-Watamu Reserve within Watamu MPA (olive green) is a Low Use Zone, with respect to recreational activities.
    [Show full text]
  • 001 Mombasa 001 Changamwe 147,613 16.00 0001 Port Reitz 31,720 4.00 Comprises Part of Port Reitz Sub–Location Mombasa Coun
    Ward No. Ward Name Ward Population Ward In Sq. Area Ward Description Ward County No. County Name Constituency No. Constituency Constituency Area Constituency Assembly County Assembly County Assembly County Assembly County Assembly County In Sq. Km Km (Approx.) (Approx.) Name Population (Approx.) 001 Mombasa 001 Changamwe 147,613 16.00 0001 Port Reitz 31,720 4.00 Comprises Part of Port Reitz Sub–Location Mombasa County 0002 Kipevu 29,100 2.10 Comprises Part of Chaani Sub–Location of Mombasa County 0003 Airport 31,721 4.00 Comprises Part of Portreitz Sub–Location of Mombasa County 0004 Miritini 25,934 3.80 Comprises Miritini Sub–Location of Mombasa County 0005 Chaani 29,138 2.10 Comprises Part of Chaani Sub–Location of Mombasa County 001 Mombasa 002 Jomvu 102,566 29.00 0006 Jomvu Kuu 38,776 19.00 Comprises Jomvu Kuu Sub–Location of Mombasa County 0007 Magongo 11,013 3.80 Comprises Changamwe Sub–Location of Mombasa County 0008 Mikindani 52,777 6.20 Comprises Kwa Shee and Birikani Sub–Locations of Mombasa County 001 Mombasa 003 Kisauni 194,065 88.70 Page 1 Ward No. Ward Name Ward Population Ward In Sq. Area Ward Description Ward County No. County Name Constituency No. Constituency Constituency Area Constituency Assembly County Assembly County Assembly County Assembly County Assembly County In Sq. Km Km (Approx.) (Approx.) Name Population (Approx.) 0009 Mjambere 27,573 4.15 Comprises Part of Magongoni Sub–Location of Mombasa County 0010 Junda 39,432 7.50 Comprises Comprises Junda Sub–Location of Mombasa County 0011 Bamburi 24,918 12.30 Comprises
    [Show full text]
  • Kenya Marine Mammal Network
    Issue 1, May 2012 WELCOME to the Kenya Marine Mammal Network Relatively little is known about the marine mammal species around Kenya. The scarce knowledge on these species is based on data collected during aerial survey conducted between 1994 and 2001, and information from stranded animals. Since then, some of these species have been in constant decline in the Western Indian Ocean, facing real threats such as by-catch in fishing gears, loss of habitat, overfishing or whale/dolphin-watching activities. For these reasons, there is an urgent need to gain a more comprehensive data set for these species. Introducing opportunistic sightings can be an economical resource as well as a vital contribution to achieving this larger data. Opportunistic sighting surveys can be defined as species data collection from non-scientific vessels and persons who regularly frequent the seas. This activity has been undertaken in many countries throughout the world where either limited scientific research has taken place and/or to bolster data collection from a wider, often multinational area. This network aims to provide the first consistent data on occurrence and abundance of marine mammals along the Kenyan coast collected by sport fishing vessels, diving clubs and NGOs as a platform of opportunity. Also, this project will help to define areas of “High Importance” for marine mammals, which will improve our understanding of these species in this region and on a broader temporal scale. At the same time, this data is extremely important for the marine mammal conservation and management strategies in Kenya and it may be used as a baseline for further studies.
    [Show full text]
  • Protection of Marine Areas in Kenya
    Protection of Marine Areas in Kenya Arthur Tuda and Mohamed Omar The need for marine protected areas Kenya has a rich diversity of marine and coastal ecosystems. These ecosystems in - clude mangrove wetlands, coastal forests, estuaries, sandy beaches and sand dunes, coral reefs, and seagrass beds that support a host of marine and coastal species. The ecosystems constitute an important life-support system for local communities. They supply vital resources that support livelihoods and economic development. Additionally, these ecosys- tems maintain the health of marine and coastal landscapes and seascapes at large. The Kenyan coast is also endowed with a rich history of social and cultural interactions and traditions that span the entire shoreline. Notable amongst these traditions are the social, cultural, and economic opportunities that have been provided to the Kenyan coastal popu- lation through the use of the marine and coastal ecosystems for food, trade, recreation, and transport (Government of Kenya 2011). It is reported that trade in mangrove poles sur- passed tourism and agriculture in foreign earnings in colonial times. To this day, opportuni- ties for employment, tourism, and recreation provided by the marine and coastal environ- ment and its resources, continue to make considerable contribution to the Kenyan economy. It estimated that more than 60% of tourists visiting Kenya must pass through the coast. However, immense pressure has been exerted on Kenya’s marine resources by the ever- increasing human population and demand for natural resources. Consequently, Kenya’s marine environment, ecosystems, and associated resources have shown signs of degradation due to over-exploitation as a result of unregulated use.
    [Show full text]
  • Sea Surface Temperature in the Western and Central
    CORAL AND ALGAL RESPONSE TO THE 1998 EL NIÑO CORAL BLEACHING AND MORTALITY ON KENYA’S SOUTHERN REEF LAGOONS Tim R. McClanahan and Steven Mangi Coral Reef Conservation Project, Mombasa, Kenya INTRODUCTION The 1998 interaction between the El Niño and the Indian Ocean dipole produced one of the warmest years in recent records (McPhaden, 1999; Saji, 1999; Webster et al., 1999) and is reported to have caused extensive coral bleaching and mortality throughout the western Indian Ocean (Strong et al., 1998; Goreau et al., 1999; Wilkinson et al., 1999). Previous observations of coral bleaching in Kenya were recorded in 1987 and 1994 with the 1987 event causing significant mortality in corals and other benthic invertebrates (McClanahan, unpublished data and observations). The East African coast has a strong seasonal cycle and these bleaching events occurred at the end of the warm north-east monsoon, usually beginning in March, during the local annual peak of solar irradiance and water temperature (McClanahan, 1988). The recent 1998 coral bleaching event was the most severe in terms of the mortality of benthic organisms, particularly corals, and, therefore, efforts were made to document this event and to determine the sensitivity of coral genera to this disturbance, the role of reef management and in particular, the role of herbivory, on the ecological outcome of this coral mortality. Coral mortality from bleaching or other factors has been shown to produce a variety of responses in coral reef benthic communities (Brown, 1997). These range from quick recovery of coral cover and species composition (Brown, 1997), switches in coral species dominance (Aronson & Precht, 1997; Greenstein et al., 1998), overgrowth of bare substrate by erect fleshy algae (Shulman & Robertson, 1997; McClanahan et al., 1999), near extirpation of species (Glynn & Feingold, 1992), to the destruction of reef framework by bioeroding organisms (Glynn, 1988; Eakin, 1996).
    [Show full text]