Anderwald, P. (Pia)

Evans, P.G.H. (Peter)

Gibas, D. (Danielle)

Pierce, G.J. (Graham John)

Quer, S. (Susanna)

Santos, M.B. (María Begoña)

Veneruso, G. (Gemma)

Weir, C.R. (Caroline)

English

Repositorio Institucional Digital del IEO

Using land watch data to determine long-term trends in cetacean abundance Graham Pierce, Peter Evans, Gemma Veneruso, Caroline Weir, Danielle Gibas, Pia Anderwald, Susanna Quer, Vasilis Valavanis, James Waggitt & Begoña SantosSea Watch Foundation - Land watch data• Citizen science – pros and cons• Since 1965…• Choice of site on the basis of raised elevation, good field of view, and safety• Timing depends on good weather, NOT on sighting cetaceans!• Usually 1 or sometimes 2 primary observers (recorded)• Naked eye scans plus binoculars to verify species & group size• Environmental informationrecorded at start & end of watch, 15-min or 30-min intervals, or if conditions changed• Plus instantaneous scan counts at regular intervals (separate)Bottlenose Dolphin  Maps from: Reid, Evans & Northridge (2003). Atlas of Cetacean Distribution in Northwest European Waters• Both protected under EU Habitats DirectiveHarbour Porpoise • Widely distributed, more abundant• Predominantly coastal, 2 main local populationsStudy Aims: Questions1) Can land watch data reveal spatial and temporal trends in bottlenose dolphin and harbour porpoise distribution and local abundance in UK waters?2)Are there coastal hotspots which could be recommended as “Special Areas of Conservation”?3)What improvements to land watch methodologies would maximise the value of the data collected?Summary of UK land watch data & analysis • >145,000 effort records• c. 84,000 hours of effort• 50-year time period: 1965-2014• 732 sites• c. 20,000 harbour porpoise records• c. 27,000 bottlenose dolphin records• Presence, sighting and count rates• Results summarised by site-day (remove within-day AC)• Remove repeat sightings, missing and high sea state values• GAMs, by species, time period• Account for sea state, elevation, observation duration, etc• Quantify spatial, temporal, environmental patternsPoint Lynas, AngleseyLundy Island, DevonLand Watch Effort by MonthLand Watch Effort by YearDistribution of effort by month, year, areaJ   F   M    A    M    J     J A    S    O    N    D1970       1980      1990       2000      2010Land Watch Effort by AreaResults #1. Distribution of bottlenose dolphin & harbour porpoise (1990-2004): Presence, SPUE and IPUE by sitea) Bottlenose Dolphin b) Harbour PorpoisePresenceSPUEIPUENorthScotlandEastScotlandEasternEnglandS/SWEnglandWalesWestScotlandNWEnglandPresenceSPUEIPUENorthScotlandEastScotlandEasternEnglandS/SWEnglandWalesWestScotlandNWEnglandDistribution (1990-2004): Map of GAM predicted likelihood of occurrence for Bottlenose DolphinPredicted             Upper 95%        Lower 95%            Predicted             Upper 95%        Lower 95%              Distribution (1990-2004): Map of GAM predicted likelihood of occurrence for Harbour PorpoiseEnvironmental correlates of (coastal) sighting rate (1990-2004)a) Bottlenose Dolphin b) Harbour PorpoiseDepth - shallowerSlope -steeperAspect – S facingDepth - deeperSlope -steeperAspect NE facingSST - higher St Dev depth - smootherData: monthly, 5 km x 5 kmSource: Baines & Evans (2012)Atlas of Marine Mammals of WalesResults #2. Agreement with at-sea survey results: Predicted likelihood of occurrence for Harbour Porpoise Celtic & Irish Sea Assessment Unit Results #3: bottlenose dolphins versus porpoisesSouthern Cardigan Bay, 13 June 2014Distribution of uk-stranded porpoises killed by bottlenose dolphinsZSL SCOTLANDWALES & ENGLAND0.00.20.40.60.81.01.21.4Lamba Ness, UnstBelmont VP, Unst, Bluemull SoundBurra Voe (from North Voe)Lunna NessLunning Sound from LunningHuxterBurrastow/Vaila Sound - actually from StapnessScarvisterTurr Ness, NossWester QuarffMousa South SiteBoddam (OutVoe)Hundland, Papa WestrayHoxa Head, South RonaldsayUshat HeadDunnet Head (West)Wick A or BBadbeaGolspie PierRockfieldRosemarkieKessock Bridge, InvernessFindhorn BayBurghead EastHopeman CavesLossiemouth Coastguard StationKingston by River SpeyFindochty/Findochty ChurchCullen Bay near Scar NosePortsoyKinnaird Head, By FraserburghPeterheadHackley BayAberdeen BeachSouter Head, CoveDownie Point, StonehavenJohnshaven south of InverbervieElliot Links, south of ArbroathFarne Islands (Inner Farne LH)Amble Sand Dunes / opp. Coquet IslandRocky Island, Seaton SluiceLizard Point, MardsenStaithesFiley BayThe Deep, HullWinthorpe Tower, SkegnessSheringhamPakefield Cliffs south of LowestoftBroadstairsBirling GapPoole BayDawlish Warren west of ExmouthSlapton SandsBolt Head, DevonStoke Beach, Noss MayoPort Wrinkle west of PlymouthNare Point (Lizard Peninsula)PorthlevenPeninnis Head, Isles of ScillyPortreath south of St AgnesBoscastleGreencliffSaunton Beach, south of Croyde BayBull PointWatermouth, west of Combe MartinBrean DownOgmore-by-seaPort Eynon PointMilford HavenDeer Park, Martin's HavenCastell Coch, near AbercastlePoppit YHMwntNew Quay HeadlandAberystwyth CastleTal-y-bont, north of BarmouthBardsey IslandSt Mary's Well, Bardsey IslandNorth StackWylfa HeadAmlwch BoncPenmonPort St. MaryBallaquaneSeacombe ferry terminalSt Chads, BlackpoolHeyshamSillothPortpatrick, Dunskey CastleSalen Cemetery car park, Isle of MullIsle of Eigg (Glebe)Melvaig Inn, GairlochCulkein, StoerStrathy Point A or BBerneray (North), North UistMagilligan PointGrey Point, Belfast LoughHarbour porpoiseBottlenose dolphinBottlenose dolphin vs harbour porpoise distributionsNorthScotlandEastScotland    Eas rEngland/SWEnglandWales WestScotlandNWEnglandSiteLocal abundanceResults #4. Long-term trends in presence of bottlenose dolphin and harbour porpoiseb) Harbour Porpoisea) Bottlenose DolphinRegional long-term trends in presence of bottlenose dolphin and harbour porpoisea) Bottlenose Dolphin b) Harbour Porpoise1990201419902014HighHighLowLowNorthumberland toSouth DevonN = 112 sitesEast Grampian toNorthumberlandN = 56 sitesSUMMARY• c. 84,000 hours of land watch effort from c. 700 sites around the UK; most data in recent years• Overall good but somewhat uneven spatial coverage• Bottlenose dolphins concentrated in Eastern Scotland and West Wales, mirroring offshore survey information• Harbour porpoises concentrations in N & E Scotland, Eastern England, SW & N Wales, and West Scotland. Coastal hotspots are consistent with offshore surveys• Coastal distributions of the 2 species are inversely related• Bottlenose dolphins increased since 2006; porpoises  decreased since 2000, with regional variation• Land watch data can supplement vessel/aerial surveys and provide early indications of population changeACKNOWLEDGEMENTSFunding for Analyses• UK Joint Nature Conservation CommitteeData Contributors• Sea Watch Observers• Ceredigion County Council• National Oceanography Centre• Whale & Dolphin Conservation• MANW and The Wildlife Trusts• European Marine Energy Centre• IWDG, HWDT, ORCA and MarineLife• HCMR

Using land watch data to determine long-term trends in cetacean abundance

http://www.repositorio.ieo.es/e-ieo/bitstream/10508/10075/4/Pierce%20et%20al%20SMM%20Land%20Watch%20talk%20updated.pdf

Using land watch data to determine long-term trends in cetacean abundance

Abstract

Similar works

Full text

Available Versions

Repositorio Institucional Digital del IEO