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The seabird wreck in the Bay of Biscay and South-Western Approaches in 2014: A review of reported mortality

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Between December 2013 and February 2014, a series of storm events occurred in areas of the North Atlantic frequented by migratory seabirds. Prolonged exposure to sustained storm conditions was followed by an unprecedented level of seabird mortality, apparently due to starvation, exhaustion and drowning. A total of 54,982 wrecked birds was recorded along European coastlines of the North-East Atlantic over the winter; 94% of which were dead. The majority of birds found were recorded on the French coastline (79.6%), and the most impacted species was the Atlantic Puffin Fratercula arctica (53.5%). In this paper, we describe the conditions surrounding this wreck event and report the numbers of wrecked and stranded seabirds by combining reports from multiple affected countries.
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SEABIRD 29 (2016): 22–38
22
Reported mortality in the 2013/14 NE Atlantic seabird wreck
The seabird wreck in the Bay of Biscay
and Southwest Approaches in 2014: A
review of reported mortality
Tim I. Morley1*, Annette L. Fayet2, Helene Jessop3, Paul Veron4, Merlin Veron5,
Jacquie Clark6and Matt J. Wood7
* Correspondence author. Email: t.i.m-eee09@hotmail.co.uk
1Alderney Wildlife Trust, Slades, 48 Victoria Street, Alderney, GY9 3TA,
Channel Islands;
2Department of Zoology, University of Oxford, Oxford OX1 3PS, UK;
3RSPB, Keble House, Southernay Gardens, Exeter, Devon, EX1 1NT, UK;
4Mermaid Cottage, Mannez Lighthouse, Alderney, GY9 3YJ, Channel Islands;
5Le Grand Verger, Rue Des Marais, Vale, Guernsey, GY6 8AU, Channel Islands;
6British Trust for Ornithology, The Nunnery, Thetford, IP24 2PU, UK;
7School of Natural & Social Sciences, University of Gloucestershire,
Cheltenham GL50 4AZ, UK.
Abstract
Between December 2013 and February 2014, a series of storm events occurred in
areas of the North Atlantic frequented by migratory seabirds. Prolonged exposure
to sustained storm conditions was followed by an unprecedented level of seabird
mortality, apparently due to starvation, exhaustion and drowning. A total of 54,982
wrecked birds was recorded along European coastlines of the northeast Atlantic
over the winter; 94% of which were dead. The majority of birds found were
recorded on the French coastline (79.6%), and the most impacted species was the
Atlantic Puffin Fratercula arctica (53.6%). In this paper, we describe the conditions
surrounding this wreck event and report the numbers of wrecked and stranded
seabirds by combining reports from multiple affected countries.
Introduction
Seabird wrecks occur when large numbers of dead, injured or exhausted seabirds
wash up on coastlines with no obvious cause of death (Birkhead 2014). Such
events are extremely hard to quantify because most mortality occurs at sea. Even
when birds do wash ashore they often do so in inaccessible locations, such as at
the bottom of steep cliff shorelines. Despite these challenges, it is important to
attempt to quantify the magnitude of wreck events and put them into context
with other wrecks to inform long-term studies of seabird population dynamics,
because they can have large impacts on seabird populations (Votier et al. 2005,
2008; Mesquita et al. 2015).
Between December 2013 and February 2014 a succession of extreme and persistent
weather events generated such severe conditions that a number of seabird species,
usually wintering in the open ocean, were adversely affected. Although no individual
23
SEABIRD 29 (2016): 22–38
Reported mortality in the 2013/14 NE Atlantic seabird wreck
Table 1. Known survey effort within affected areas.
Country Date Location Distance Source
United Kingdom 22–23 February Accessible coastline 1,984 km Schmitt 2014
throughout the UK
excluding the southwest
England region*
Channel Islands: Regular surveys 6.51 km of 77.18 km total Broadhurst &
Alderney from 10 February accessible Morley 2014
to 22 March coastline
Channel Islands: 22 February Accessible 96 km total C. Veron, pers. comm.
Guernsey to 8 March coastline
Channel Islands: 16–23 February, Accessible Variations in personnel G. Young &
Jersey 2–9 March coastline make total distance C. Sellares,
incalculable pers. comm.
France Six weekends from French Atlantic Surveys conducted Farque et al.
1 February to coastline across 2,773.7 km but 2014
9 March 2014 not all was accessible
Spain Some areas regular, Atlantic and Varying effort in C. Torrell,
others intermittent northern Spanish different locations pers. comm.
coastlines makes distance
incalculable
Portugal 14–27 March 12.7 km of accessible 22.7 km total T. van Nus,
coastline between pers comm.
Sao Jacinto and Torreira,
northwest Portugal
* SW region could not be surveyed on the designated days due to weather
storm was an exceptional event, the clustering and persistence of the storms was
highly unusual (Slingo et al. 2014). The storms occurred from the first week of
December 2013, through January and into early February 2014 causing record wind
gusts (> 60 knots) and rainfall in the UK (Slingo et al. 2014). A notable feature of
the storms was the long peak wave period and high wave height, resulting in waves
carrying a large amount of energy causing substantial damage to northeast Atlantic
coasts; presumably conditions at sea for wintering seabirds must have been similarly
extreme. Conditions also included an unusually strong North Atlantic jet stream and
a prolonged series of storm events, with winds gusting in excess of 100 mph; the
worst recorded for a century (Slingo et al. 2014).
Tracking studies have shown that several seabird species including Atlantic Puffin
Fratercula arctica, hereafter ‘Puffin’ (Guilford et al. 2011; Jessopp et al. 2013; Fayet
et al. 2016), Common Guillemot Uria aalge, hereafter ‘Guillemot’ (Stone et al.
1995), Northern Gannets Morus bassanus, hereafter ‘Gannet’, from the UK and
Norway (Veron & Lawlor 2009; Fort et al. 2012), and Black-legged Kittiwakes Rissa
tridactyla, hereafter ‘Kittiwake’, from Western Europe (Frederiksen et al. 2012),
would have been in the Celtic Sea, Bay of Biscay and/or western English Channel
SEABIRD 29 (2016): 22–38
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Reported mortality in the 2013/14 NE Atlantic seabird wreck
during late winter (January–February), and therefore at risk of being affected by the
storm events during this period. Large numbers of dead and injured seabirds were
subsequently washed ashore over much of the northeast Atlantic coast of Europe,
as ocean currents and wind carried dead and moribund birds ashore.
This paper attempts to give a detailed report of the mortality associated with the
2013/14 seabird wreck by combining beached bird surveys from across the entire
affected area. Information will be provided on the origin of the species most
affected by the wreck using ring recovery data; note that data were available from
the UK only for this review. We also report evidence on cause of death from post-
mortem examinations of dead seabirds.
Methods
Survey of stranded seabirds: The methods used by different organisations or
volunteers in different countries were sufficiently similar to warrant comparison.
Typically, a designated route along an accessible coastal area, usually sandy beaches
but including all accessible coastline habitats, is walked by surveyors standing a
distance apart that allows the maximum amount of beach area to be covered in one
transect as they scanned the location for specimens. This methodology accords very
closely with that of the Royal Society for the Protection of Birds’ (RSPB) ‘Beached
Bird Survey’ which coincided with the 2013/14 wreck, conducted on its annual
schedule in the UK on 2223 February (Schmitt 2014). Not all surveys in all areas
of the UK (Figure 1) would have been through the RSPB scheme, due to the reactive
approach to seabird wrecks, but many of them were (Table 1).
Besides the survey effort described in Table 1, additional data were gathered from
members of the public. These records were subsequently confirmed and verified
by the relevant organisation, minimising the chances of double-counting
individuals by cross-checking against previous reports from the same location and
confirming identification from photos where available. All these data are included
in the totals given. Despite the coordinated Beached Bird Survey in parts of the
UK and France, and continued major survey effort across multiple locations
providing a considerable amount of data on the seabird wreck, the challenges
involved in collating and continuing surveys across such a large area, the varying
search effort between organisations around the period of the wreck, the discovery
of only a proportion of the fatalities occurring at sea and the varying time that
different species of seabird corpses will remain afloat, are likely to result in a
substantial underestimation of mortality.
Post-mortem examinations: To determine cause of death, staff from the Groupe
Ornithologique Normand, Alderney Wildlife Trust and Alderney Animal Welfare
conducted a necropsy workshop in Alderney on 22–23 March 2014. Subcutaneous
fat (between the feathers on the breast), fat deposits around the distal part of the
gut, curvature of pectoral muscle extending from the sternum and presence of
spume in the lungs were recorded, alongside general information on the state of the
specimens, to determine any potential cause of death (Broadhurst & Morley 2014).
25
SEABIRD 29 (2016): 22–38
Reported mortality in the 2013/14 NE Atlantic seabird wreck
Ringing recoveries: Ringing recoveries reported to the British Trust for
Ornithology (BTO) over the wreck period were analysed. Only recoveries
occurring between December 2013 and March 2014 were included. We limited
the analysis to the recoveries made in the area affected by the storms, including
the French, Spanish and Portuguese Atlantic coasts, the coast along the English
Figure 1. Location of survey areas recorded during the seabird wreck event (red line).
05001,000250
km
N
SEABIRD 29 (2016): 22–38
26
Reported mortality in the 2013/14 NE Atlantic seabird wreck
Results
Estimates of mortality: In total, 54,982 birds were found during the survey
period; of these 3,243 (5.9%) were live birds. The majority of the birds was found
in France (79.6%) and Puffins were by far the species most impacted (53.6%;
Table 2). Of the live birds retrieved, 3,014 (93%) were found in France, most likely
due to currents and proximity to this coastline during the storm events. Of these
a third subsequently died in transit, a third died in care and a third were
successfully released back into the wild (Farque et al. 2014). The only other
locations in which live birds were recorded were in Guernsey (18 Guillemots and
one Gannet), southwest England (209 birds) and Wales (one Guillemot).
Channel, and the Irish and British coast of the Celtic and Irish Seas (Figure 1).
Note, all recoveries originated from British colonies (Figure 2). Causes of death for
inland recoveries are uncertain, with factors other than the storms potentially
impacting the birds, whilst the death of many birds recovered during the time
period of the wreck was not linked to the storms (e.g. disease or shot); all these
recoveries were excluded from the results.
Figure 2. Origin colonies of ring recoveries recorded on the northeast Atlantic coast of Europe between
December 2013 and March 2014, for the four main species affected (Puffin Fratercula arctica, Guillemot Uria
aalge, Razorbill Alca torda and Shag Phalacrocorax aristotelis); colonies with more than one recovery labelled.
015030075 km
N
Lunga
Port Ban
Fair Isle
Sule Skerry
Leac Buidhe
Isle of May
Faraid Head
Calf of Man
Ailsa Craig
Sanda Island
Great Saltee
Garbh Eilean
Castle Craig
Skomer Island
Puffin Island
Porth Ysgaden
Lambay Island
Isle of Canna
Great Skellig
Ceann Ousdale
Bardsey Island Ynys Gwylan Islands
Number of recoveries
1–2
3–8
9–24
25–61
62–157
Pen y Parc
27
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Reported mortality in the 2013/14 NE Atlantic seabird wreck
Table 2. Numbers of wrecked seabirds (live strandings and dead birds combined) recorded on the northeast
Atlantic coast of Europe from January to April 2014.
Channel SW Rest of UK
Species Portugal Spain France Islands England Wales & Ireland1Total
Gannet 5 67 305 8 33 54427
Fulmar 14131 43 7 15 165
Shag 12 47 110 22 10192
Kittiwake 5 51 868 31 29 20 73 1,077
Puffin 121 277 28,745 119 115 25 42 29,444
Razorbill 9 99 1,197 468 902 234 911 3,820
Guillemot 0 1,538 11,801 441 1,311 139 713 15,943
Auk spp. 1 85 254 16 590 22950
Other seabirds 14 105 229 43 53 7 33 484
Non-seabirds 6 12 176 48 50 5 252
Unidentified 13 022762217 1,729 2,228
Total 163 2,253 43,753 1,290 3,339 657 3,527 54,982
1Region encompasses data from Ireland, Northern Ireland, Scotland, Shetland and England (except the southwest region).
2Value includes 209 live birds retrieved but species composition was not recorded, likely mostly auks.
Post-mortem examinations: Necropsy analyses conducted on a sample of 12
Guillemots in Alderney showed that 58% had emaciated pectoral muscles, 92%
had no stomach contents (no data available for the final bird), 83% had no fat on
the chest and 50% had some or no fat in the intestine, indicating that starvation
was the most likely cause of death (Broadhurst & Morley 2014). In addition,
specimens of Guillemot and Razorbill Alca torda, hereafter ‘Razorbill’, were
collected on Chesil Beach, Dorset, on 2 March 2014 (P. Read pers. comm.). Although
data on time since stranding were unavailable, the mean (± SD) masses were 451.9
± 53.9 g (n = 44) for the Razorbills and 601.5 ± 85.5 g (n = 17) for the Guillemots.
Winter weight of healthy individuals is difficult to attain, but Guillemots are likely
in the range of 900–1,200 g (Hope Jones et al. 1984). Values for Razorbill are harder
to come by still but likely higher than the average weight of the wreck individuals.
Furthermore, live birds collected in France were emaciated and extremely weak,
typically weighing less than half that of a healthy adult (O. Le Gall, pers. comm.).
The Animal Health and Veterinary Laboratories Agency (AHVLA) also necropsied 27
seabirds from the wreck, primarily Razorbills and Guillemots, all of which were
emaciated (AHVLA 2014). The presence of spume (frothy water) in the lungs was
noted by the AHVLA (AHVLA 2014) and recorded in three specimens in the
Alderney Guillemot autopsy (Broadhurst & Morley 2014).
Finally, only 10 (3.3%) out of 300 wrecked Puffins whose wings were examined were in
moult to such an extent that they would have been flightless (M.P. Harris pers. comm.).
Ring recovery data: Since the first recovery of a ringed Puffin was made in
1935/36, the BTO have recorded an average of 11.5 recoveries of ringed Puffins
washed ashore dead in the UK per winter (November to April) up until 2012/13; a
maximum of 127 recoveries were reported in the winter of 1982/83. Additionally,
SEABIRD 29 (2016): 22–38
28
Reported mortality in the 2013/14 NE Atlantic seabird wreck
recoveries of dead ringed Puffins from France and Spain would normally equal two
or three a year (Grantham & Stancliffe 2014). However, during the wreck, 631
ringed birds were recovered, including 216 Puffins, of which 205 were from France
(Tables 3 and 4). The recoveries were spread across the entire impacted area, but
Table 3. Recovery locations of ringed seabirds found wrecked on the northeast Atlantic coast of Europe
between December 2013 and March 2014, as registered by the British Trust for Ornithology.
Channel UK &
Species Portugal Spain France Islands Ireland Total
Gannet 112 6 10
Fulmar 22
Shag 50 50
Cormorant 11 9 11
Kittiwake 178
Herring Gull 77
Great Black-backed Gull 44
Lesser Black-backed Gull 21 3
Black-headed Gull 44
Puffin 15205 14 216
Razorbill 1226 1 126 156
Guillemot 6 90 3 44 143
Black Guillemot 17 17
Total 5 17 324 5 280 631
Table 4. Ringing locations of ringed seabirds wrecked on the northeast Atlantic coast of Europe between
December 2013 and March 2014, as registered by the British Trust for Ornithology.
Northern
Ireland and Isle of Rest of
Species Ireland England Scotland Wales Man Europe* Total
Gannet 441110
Fulmar 112
Shag 72427 10 50
Cormorant 2126 11
Kittiwake 21 5 8
Herring Gull 2113 7
Great Black-backed Gull 44
Lesser Black-backed Gull 12 3
Black-headed Gull 11 2 4
Puffin 5 196 15 216
Razorbill 29 72 50 5 156
Guillemot 29 74 40 143
Black Guillemot 11 6 17
Total 89 13 357 141 18 13 631
* Including data from Belgium, France, Finland, Iceland and Norway.
Figure 3 (overleaf). Colony origin of ringed auks and Shags Phalacrocorax aristotelis (for colonies contributing
more than 5 recoveries) recovered on the northeast Atlantic coast of Europe between December 2013 and
March 2014, as registered by the British Trust for Ornithology.
29
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Reported mortality in the 2013/14 NE Atlantic seabird wreck
Garbh Eilean
Skomer
Lunga
Sule Skerry
0250500125
km
N
3a) Puffin
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30
Reported mortality in the 2013/14 NE Atlantic seabird wreck
Great Saltee
Skomer
Canna
Puffin Island
Sanda
0250500125
km
N
3b) Guillemot
31
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Reported mortality in the 2013/14 NE Atlantic seabird wreck
3c) Razorbill
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Reported mortality in the 2013/14 NE Atlantic seabird wreck
Calf of Man
Lambay
Puffin Island
Ynys Gwyland
Porth Ysgaden
N
0 100 20050
km
3d) Shag
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Reported mortality in the 2013/14 NE Atlantic seabird wreck
certain UK colonies were seemingly represented in higher numbers than others
(Figures 2 and 3). Data were filtered to remove any ring recoveries during the wreck
time period that were not attributable to the storm conditions; therefore, we only
included recoveries of birds with ‘unknown’ (53.57%) or ‘natural’ (42.95%; predom-
inantly attributed to ‘violent weather’) recorded as the cause of death. Ring
recoveries of oiled birds (3.49%) were also recorded within the wreck event as
specimens from other locations showed signs of oiling without it necessarily being
the final cause of mortality (AHVLA 2014; Broadhurst & Morley 2014).
Discussion
A total of 54,982 birds was recorded during the 2013/14 northeast Atlantic seabird
wreck, 79.6% of which were found in France. This number is likely to be a large
underestimate of the final death toll, due to the limited surveying across all regions
impacted. Also, many birds that perish in storms may not be washed ashore, the
proportion of which can only be estimated by drift experiments made during the
incident (Weise 2003). However, with such a large level of mortality (94% of the
birds, of which 53.6% were Puffins, were found dead), it is important to consider
potential factors that may have affected the severity of the wreck event.
Causes of mortality: The ringing recoveries recorded by the BTO attribute 42.3%
of mortality to ‘violent weather’; this is the likely overall cause, but more specif-
ically several independent lines of evidence point to starvation as the most likely
direct explanation for the extensive mortality observed in the 2013/14 seabird
wreck. Autopsy data from Alderney (Broadhurst & Morley 2014), Chesil Beach (P.
Read pers. comm.) and the AHVLA (AHVLA 2014) all show marked levels of
emaciated body condition in analysed specimens. The recording of weight of dead
birds comes with the caveat that many corpses are found in a desiccated state,
potentially overestimating the amount of weight loss. However, the Alderney
autopsy states that 50% of specimens were fresh and 25% rather fresh, reducing
the likelihood of desiccation after death being a major factor for these results.
Although starvation is the main factor in cause of mortality, evidence of drowning,
such as spume in lungs, was also noted in some specimens (AHVLA 2014;
Broadhurst & Morley 2014).
Many factors are likely to affect the susceptibility of different species or
individuals to death from starvation or drowning. Seabirds spend a significant
amount of time and energy foraging in winter, particularly in November and
December, to regain body condition for the breeding season (e.g. Daunt et al.
2006; Fort et al. 2009), so challenging winter conditions sustained over several
weeks or, as in this case, months are likely to affect the birds’ foraging opportu-
nities with possible consequences on their future condition, survival and
reproductive ability. For example, European Shags Phalacrocorax aristotelis,
hereafter ‘Shags’, have been shown to forage less during times of high wind
speeds, with males foraging for shorter times than females which could have
consequences for sex-specific survival rates (Lewis et al. 2015), and they may
even halt diving altogether during high onshore gales (Frederiksen et al. 2008).
SEABIRD 29 (2016): 22–38
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Reported mortality in the 2013/14 NE Atlantic seabird wreck
Additionally, the continued turbid water conditions associated with storms may
create poor visibility for foraging. This is a particular issue for auks which have
less flexible foraging strategies than Shags (Watanuki et al. 2008; Cook & Burton
2010) and spend more energy on longer, deeper dives (Elliott et al. 2013; Elliott
& Gaston 2014) to pass through the turbid surface conditions, possibly causing
the energetic cost of foraging to outweigh the nutritional gain from successful
catches. The fact that the overwhelming majority (91.3%) of retrieved birds
during the 2013/14 seabird wreck belonged to the auk family supports difficult
foraging conditions as a major contributor to mortality.
In addition to considering the weather conditions, the habits of the species found
must also be considered; susceptibility may vary between pelagic and inshore
species and between long- and short-ranging species. Pelagic seabirds were the
most impacted during the wreck, accounting for 92.5% of all findings (auks alone
were 91.3%), whilst inshore species contributed just 3.3% of all findings (Table 2)
suggesting they were less susceptible to the conditions created by the storms.
Findings from a small number of Puffins carrying geolocation loggers also suggest
that the migratory patterns of some individuals may make them more susceptible
to suffer from a wreck than others (A. Fayet et al. unpubl. data). Moult stage could
be another factor adding to birds’ susceptibility to a wreck event. For example,
Puffins shed all their main wing feathers synchronously during the winter (Harris
& Yule 1977) and are then unable to fly for a few weeks (Harris 2014; Harris et al.
2014). However, the small number of moulting Puffins found suggests moult was
not an important factor in this wreck (M.P. Harris pers. comm.). Nevertheless, it
cannot be totally disregarded, given the variability in the timing of Puffin moult
(Harris et al. 2014) and the role of post-moult feather growth in the Razorbill
wreck in 2007 (Heubeck et al. 2011).
Besides differences in foraging, migratory strategies, and habitat use, the physio-
logical differences between species could also have affected mortality rates. For
instance, the partially wettable plumage of Shags (Grémillet et al. 1998) increases
mortality in times of low ambient temperature, most likely through hypothermia
(Frederiksen et al. 2008). The ability to survive through a wreck event may also be
linked to body size, with larger-bodied species retaining greater energy reserves.
Finally, metabolism could also play a role, as suggested by Hope Jones et al. (1984)
who discovered a higher percentage of Razorbills to have lower fat reserves on
autopsy than Guillemots following the 1983 seabird wreck. However, the small
samples examined of these species from the 2013/14 wreck are insufficient to
provide any further evidence on the role of metabolism, particularly as weight loss
was high for both species. A recent study of some specimens showed, however, that
high concentrations of mercury (known to increase stress) may have acted as an
aggravating mortality factor during the event (Fort et al. 2015).
Impacts of mortality: Whilst the majority of wreck birds were located in France
(Tables 2 and 3), most ringed birds were from breeding colonies in Scotland, Wales
and Ireland (Table 4). This is to be expected as most of the large seabird colonies
35
SEABIRD 29 (2016): 22–38
Reported mortality in the 2013/14 NE Atlantic seabird wreck
where BTO-licensed ringers operate are in these locations, but it does highlight
the possibility that reproductive success, recruitment or survival of birds from
these colonies were impacted by the wreck. Furthermore, whilst the scale of the
wreck event is staggering in terms of numbers, it is not the first event of this scale.
For example, in February and March 1994, 20,000–50,000 Guillemots and
3,000–5,000 Shags were reported washed ashore in emaciated states due to
storm events (Harris & Wanless 1996), and in February 1983 prolonged storms
across Western Europe resulted in 34,000 seabirds washing ashore in the
northeast UK alone with another 24,000 across Western Europe (Underwood &
Stowe 1984). Therefore, the regularity of wrecks impacting on a particular species
or colony should also be considered when trying to uncover any longer-term
effects at the population level.
In summary, the seabird wreck along the Atlantic coastline of northwest Europe
in winter 2013/14 was an extreme example of weather-induced mortality from
starvation in seabird populations. The subsequent impacts on population
numbers and productivity are likely to be detectable in multiple species and
colonies (M.J. Wood et al., unpubl data; T.R. Birkhead, pers. comm.). Whilst any
individual wreck can have significant consequences for the populations involved,
the frequency of wreck events is also likely to be an important factor. The
potential of climate change to increase the frequency and strength of storms
(Slingo et al. 2014; Fischer & Knutti 2015) can have severe implications for
seabird populations in the future, and the vulnerability of species to extreme
events needs to be accounted for in future predictions of ecological impacts of
climate change (Frederiksen et al. 2008).
Acknowledgements
We would like thank the hundreds of dedicated staff, volunteers and members
of the public across Western Europe who responded to the wreck event with
efforts to survey its impact. We would like to thank the organisations across
Europe that contributed to the response to and recording of the wreck,
including: Ligue pour la Protection des Oiseaux (LPO), RSPB, Cornwall, Devon
and Dorset Wildlife Trusts (and the Cornwall Marine Strandings Network and
DoWT staff at Chesil Beach, Dorset in particular), RSPCA, South Devon Seabird
Trust, BTO Ringing Scheme, National Trust, Natural England, SEO Birdlife,
Alderney Wildlife Trust, Durrell Wildlife Conservation Trust, States of Jersey,
States of Guernsey, other county Wildlife Trusts and Sussex Ornithological
Society. We would particularly like to thank the following people for their
specific help in supplying data and details on responses to the wreck event in
their location: Mike Harris (CEH, Scotland), Glyn Young (Durrell Conservation
Trust, Jersey), Cristina Sellares (National Trust, Jersey), Catherine Veron (La
Société Guernesiaise, Guernsey), Janice Dockerill (Environment Department,
Guernsey), Anne-Isabelle Boulon (Living Islands, Alderney), Ed Stubbings
(Warden Skomer Island, Wales), Bee Bueche (Warden Skomer Island, Wales),
Pembrokeshire Bird Group (Wales), Phil Read (Chesil Beach, Dorset), John
Walmsley (Newgale Beach, Wales), Tim van Nus (Portugal), Olivier le Gall (LPO,
France), Amélie Boue (LPO, France) and Albert Cama Torrell (Spain). We are also
grateful to Martin Heubeck, Viola Ross-Smith, Richard Sherley and two
anonymous referees, whose comments greatly improved this paper.
References
AHVLA 2014. ‘AHVLA Disease Surveillance Report, May 2014.’ (https://www.gov.uk/
government/uploads/system/uploads/attachment_data/file/350618/pub-survreport-
0514.pdf). Animal Health and Veterinary Laboratories Agency (AHVLA). Updated May 2014.
Accessed 24 August 2016.
Birkhead, T. 2014. ‘The Seabird Wreck of 2014.’ (http://myriadbirds.com/2014/03/03/wrecks/).
Updated 3 March 2014. Accessed 24 August 2016.
Broadhurst, M. & Morley, T. 2014.‘Alderney Wildlife Trust: Annual Ramsar Project Review 2014’.
(http://www.alderneywildlife.org/sites/default/files/annual_ramsar_project_report_2014_final.
pdf).Alderney Wildlife Trust. Updated October 2014. Accessed 24 August 2016.
Cook, A. S. C. P. & Burton, N. H. K. 2010. ‘A review of the potential impacts of marine
aggregate extraction on seabirds. Marine Environment Protection Fund Project 09/P130’.
(https://www.bto.org/sites/default/files/shared_documents/publications/research-
reports/2010/rr563.pdf). Marine Aggregate Levy Sustainability Fund. Updated August
2010. Accessed 24 August 2016.
Daunt, F., Afanasyev, V., Silk, J. R. D. & Wanless, S. 2006. Extrinsic and intrinsic
determinants of winter foraging and breeding phenology in a temperate seabird.
Behavioural Ecology and Sociobiology 59: 381–388.
Elliott, K. H. & Gaston, A. J. 2014. Dive behaviour and daily energy expenditure in
Thick-billed Murres Uria lomvia after leaving the breeding colony. Marine Ornithology
42: 183–189.
Elliott, K. H., Ricklefs, R. E., Gaston, A. J., Hatch, S. A., Speakmane, J. R. & Davorena, G. K.
2013. High flight costs, but low dive costs, in auks support the biomechanical hypothesis for
flightlessness in penguins. Proceedings of the National Academy of Sciences 110: 9380–9384.
Farque, P-A., Boue, A., Dugue, A-L. & Micol, T. 2014. ‘Echouage massif d’oiseaux marins
durant l’hiver 2014 sur la facade atlantique.’ (http://www.lpo.fr/images/actualites/
2014/echouages/bilan_echouages_2014_lpo_final1.pdf). Ligue pour la Protection des
Oiseaux (LPO) and Birdlife International. Updated July 2014. Accessed 24 August 2016.
Fayet, A. L., Freeman, R., Shoji, A., Boyle, D., Kirk, H. L., Dean, B. J., Perrins, C. M. &
Guilford, T. 2016. Drivers and fitness consequences of dispersive migration in a pelagic
seabird. Behavioral Ecology 27: 1061–1072.
Fischer, E. M. & Knutti, R. 2015.Anthropogenic contribution to global occurrence of heavy-
precipitation and high-temperature extremes. Nature Climate Change 5: 560–565.
Fort, J., Lacoue-Labarthe, T., Nguyen, H. L., Boué, A., Spitz, J. & Bustamante, P. 2015.
Mercury in wintering seabirds, an aggravating factor to winter wrecks? Science of The Total
Environment 527–528: 448–454.
Fort, J., Pettex, E., Tremblay, Y., Lorentsen, S-H., Garthe, S., Votier, S., Pons, J. B., Siorat,
F., Furness, R. W., Grecian, W. J., Bearhop, S., Montevecchi, W. A. & Grémillet, D. 2012.
Meta-population evidence of oriented chain migration in northern gannets (Morus
bassanus). Frontiers in Ecology and the Environment 10: 237–242.
SEABIRD 29 (2016): 22–38
36
Reported mortality in the 2013/14 NE Atlantic seabird wreck
37
SEABIRD 29 (2016): 22–38
Reported mortality in the 2013/14 NE Atlantic seabird wreck
Fort, J., Porter, W. P. & Grémillet, D. 2009. Thermodynamic modelling predicts energetic
bottleneck for seabirds wintering in the northwest Atlantic. Journal of Experimental Biology
212: 2483–2490.
Frederiksen, M., Børge, M., Daunt, F., Phillips, R. A., Barrett, R. T., Bogdanova, M. I., Boulinier,
T., Chardine, J. W., Chastel, O., Chivers, L. S., Christensen-Dalsgaard, S., Clément-Chastel,
C., Colhoun, K., Freeman, R., Gaston, A. J., González-Solís, J., Goutte, A., Grémillet, D.,
Guilford, T., Jensen, G. H., Krasnov, Y., Lorentsen, S-H., Mallory, M. L., Newell, M., Olsen,
B., Shaw, D., Steen, H., Strøm, H., Systad, G. H., Thórarinsson, T. L. & Anker-Nilssen, T.
2012. Multicolony tracking reveals the winter distribution of a pelagic seabird on an ocean
basin scale. Diversity and Distributions 18: 530–542.
Frederiksen, M., Daunt, F., Harris, M. P. & Wanless, S. 2008. The demographic impact of
extreme events: stochaistic weather drives survivial and population dynamics in a long
lived seabird. Journal of Animal Ecology 77: 1020–1029.
Grantham, M. & Stancliffe, P. 2014. ‘British Puffins caught up in Biscay storms.’
(http://www.bto.org/news-events/press-releases/british-puffins-caught-biscay-storms).
British Trust for Ornithology. Updated February 2014. Accessed 24 August 2016.
Grémillet, D., Tuschy, I. & Kierspel, M. 1998. Body temperature and insulation in diving
Great Cormorants and European Shags. Functional Ecology 12: 386–394.
Guilford, T., Freeman, R., Boyle, D., Dean, B., Kirk, H., Phillips, R. & Perrins, C. 2011. A
Dispersive Migration in the Atlantic Puffin and Its Implications for Migratory Navigation.
PLoS ONE 6: e21336.
Harris, M. P. 2014. Ageing Atlantic puffins Fratercula arctica in summer and winter. Seabird
27: 22–40.
Harris, M. P. & Wanless, S. 1996. Differential responses of Guillemot Uria aalge and Shag
Phalacrocorax aristotelis to a late winter wreck. Bird Study 43: 220–230.
Harris, M. P. & Yule, R. F. 1977. The moult of the Puffin Fratercula artica. Ibis 119: 535–541.
Harris, M. P., Wanless, S. & Jensen, J-K. 2014. When are Atlantic Puffins Fratercula Arctica
in the North Sea and around the Faroe Islands flightless? Bird Study 61: 182–192.
Heubeck, M., Aarvak, T., Isaksen, K., Johnsen, A., Petersen, I. K. & Anker-Nilssen, T. 2011.
Mass mortality of adult Razorbills Alca torda in the Skagerrak and North Sea area, autumn
2007. Seabird 24: 11–32.
Hope Jones, P., Barrett, C. F., Mudge, G. P. & Harris, M. P. 1984. Physical condition of auks
beached in eastern Britain during the wreck of February 1983. Bird Study 31: 95–98.
Jessopp, M. J., Cronin, M., Doyle, T. K., Wilson, M., McQuatters-Gollop, A., Newton, S. &
Phillips, R.A. 2013. Transatlantic migration by post-breeding puffins: a strategy to exploit
a temporarily abundant food resource? Marine Biology 160: 2755–2762.
Lewis, S., Phillips, R. A., Burthe, S. J., Wanless, S. & Daunt, F. 2015. Contrasting responses
of male and female foraging effort to year-round wind conditions. Journal of Animal
Ecology 84: 1490–1496.
Mesquita, M. D. S., Erikstad, K. E., Sandvik, H., Barrett, R. T., Reiertsen, T. K., Anker-
Nilssen, T., Hodges, K. I., & Bader, J. 2015. There is more to climate than the North
Atlantic Oscillation: a new perspective from climate dynamics to explain the variability in
population growth rates of a long-lived seabird. Frontiers in Ecology and Evolution 3: 43.
Schmitt, S. 2014. ‘The UK Beached Bird Survey 2014.’ (http://www.rspb.org.uk/Images/
schmitt_2014_tcm9-389064.pdf) Royal Society for the Protection of Birds. Accessed 24
August 2016.
Slingo, J., Belcher, S., Scaife, A., McCarthy, M., Saulter, A., McBeath, K., Jenkins, A.,
Huntingford, C., Marsh, T., Hannaford, J. & Parr, S. 2014. ‘The Recent Storms and Floods
in the UK.’ (http://www.metoffice.gov.uk/media/pdf/g/e/Recent_Storms_Briefing_
Final_SLR_20140210.pdf) Meteorological Office and the Centre for Ecology and
Hydrology. Updated February 2014. Accessed 24 August 2016.
Stone, C. J., Webb, A., Barton, C., Ratcliffe, T. C., Reed, M. L., Camphuysen, K. C. J. &
Pienkowski, M. W. 1995. An atlas of seabird distribution in north-west European waters.
Joint Nature Conservation Committee (JNCC), Aberdeen.
Underwood, L. A. & Stowe, T. J. 1984. Massive wreck of seabirds in Eastern Britain, 1983.
Bird Study 31: 79–88.
Veron, P. K. & Lawlor, M. P. 2009. The dispersal and migration of the Northern Gannet
Morus bassanus from Channel Islands breeding colonies. Seabird 22: 37–47.
Votier, S. C., Birkhead, T. R., Oro, D., Trinder, M., Grantham, M. J., Clark, J. A., McCleery,
R.H. & Hatchwell, B. J. 2008. Recruitment and Survival of Immature Seabirds in Relation
to Oil Spills and Climate Variability. Journal of Animal Ecology, 77: 974–983.
Votier, S. C., Hatchwell, B. J., Beckerman, A., McCleery, R. H., Hunter, F. M., Pellatt, J.,
Trinder, M. & Birkhead, T. R. 2005. Oil pollution and climate have wide-scale impacts on
seabird demographics. Ecology Letters 8: 1157–1164.
Watanuki, Y., Daunt, F., Takahashi, A., Newell, M., Wanless, S., Sato, K. & Miyazaki, N.
2008. Microhabitat use and prey capture of a bottom-feeding top predator, the European
shag, shown by camera loggers. Marine Ecology Progress Series 356: 283–293.
Weise, F. K. 2003. Sinking rates of dead birds: improving estimates of seabird mortality due
to oiling. Marine Ornithology 31: 65–70.
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... They also have high wing loading with consequent high energy flight costs (Elliott et al., 2013) which may explain why they are often found among north Atlantic seabird wrecks (e.g. Morley et al., 2016). Storms are expected to reduce survival in all three species, but species-specific differences in flight costs and winter ranges may lead to divergent effects (Clairbaux et al., 2021). ...
... vival was reduced under stormy conditions, with additive negative effects of sSST for guillemots and stronger storm effects at large population sizes for razorbills. Puffins were negatively impacted by higher wSST, and while there was no relationship with overall storminess, the winter with highest mortality (0.755 during 2013/14) coincided with high storm intensity and a major seabird wreck(Morley et al., 2016). When considering the impact of storm features separately, razorbill and guillemot survival was negatively correlated with the number of days per winter with wind speeds exceeding 30 and 35 m/s, respectively, while puffin survival was positively correlated with the mean gap duration between storms. ...
... Despite puffins comprising large proportions of winter seabird wrecks in the north Atlantic(Morley et al., 2016) we found no links between adult survival and storms. It is unclear whether this is due to our inability to detect an effect on survival, or because puffins are not impacted by storms as their very large non-breeding distribution(Figure 3a; Fayet et al., 2016) means they can move away from storms, or some combination of these factors. ...
Article
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Understanding storm impacts on marine vertebrate demography requires detailed meteorological data in tandem with long‐term population monitoring. Yet most studies use storm proxies such as the North Atlantic Oscillation Index (NAOI), potentially obfuscating a mechanistic understanding of current and future risk. Here, we investigate the impact of extratropical cyclones by extracting north Atlantic winter storm characteristics (storm number, intensity, clustering and wave conditions) and relating these with long‐term overwinter adult survival of three long‐lived sympatric seabirds which winter at sea—common guillemot Uria aalge, Atlantic puffin Fratercula arctica and razorbill Alca torda. We used multidecadal mark‐recapture analysis (1970s–2020s) to estimate survival while correcting for resighting probability, combined with spatially explicit environmental data from geolocation‐derived wintering areas, to determine the impact of different storm characteristics (i.e., number, intensity, duration, gap between storms, wave height and wind speed), as well as broad‐scale climatic conditions (NAOI and sea surface temperature [SST]). All three species experienced rapid population growth over the study period. Guillemot and razorbill survival was lower during stormier winters, with an additive effect of summer SST for guillemots, and a negative interaction with population size for razorbills. Puffin survival was negatively correlated with winter SST, and the lowest puffin survival coincided with intense winter storms and a large seabird wreck in 2013/14. The number of days with wind speed >30 and 35 ms⁻¹ negatively impacted razorbill and guillemot survival, respectively, and puffin survival was higher when gaps between storms were longer. Our results suggest negative but divergent storm impacts on these closely related sympatric breeders, which may be compounded by warmer seas and density‐dependence as these populations return to their previously much larger sizes. We tentatively suggest that frequent, long‐lasting storms with strong winds are likely to have the greatest negative impact on auk survival. Moreover, we highlight the possibility of tipping points, where only the most extreme storms, that may become more frequent in the future, have measurable impacts on seabird survival, and no effect of NAOI.
... Spain (Morley et al., 2016). These mortalities could be attributed to various factors, including extreme weather conditions such as exposure to storms and winter cyclones, leading to starvation (Clairbaux et al., 2021). ...
... However, starvation has been seen as a primary factor for massive mortality in alcids globally (Anker-Nilssen et al., 2003, 2017Diamond et al., 2020;Fullick et al., 2022;Morley et al., 2016). This F I G U R E 4 Bar plots of tissue metabolic condition of muscle and liver of Razorbill (a,b; n = 76) and Atlantic puffin (c,d; n = 10). ...
Article
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Annual mass migrations of seabirds between their breeding and wintering grounds are critical for ensuring their survival and reproductive success. It is essential to comprehend their physical condition in order to identify the causes of death and to facilitate conservation efforts. This study focuses on evaluating the age, body condition index, and metabolites in liver and muscle (triglycerides, glycerol, glycogen, cholesterol, lactate, and glucose) of stranded Razorbills (n = 84) and Atlantic puffins (n = 11). The study was conducted along the Andalusian coast of Spain during the winter season of 2022–2023. The study examined the body condition of stranded individuals and their metabolic state to determine potential factors that may have caused their deaths. The study found that the majority of stranded individuals were juveniles. Both species exhibited low levels of carbohydrate (glucose and glycogen) in their tissues and high levels of lactate in their muscles. These findings could suggest that the individuals had undergone prolonged, strenuous exercise, demanding energy on anaerobic pathways, which may have been associated with migration. The study highlights the significance of adhering to standardized protocols when assessing the body condition of stranded seabirds. Doing so can help to identify causes of death and facilitate conservation efforts. A proposed index for body condition, which incorporates biometric measurements and individual physical condition, provides a comprehensive means of understanding the health of these unique species. This study underscores the importance of further research into the conservation measures and recommendations for protecting seabird populations. It is critical to comprehend the contributing factors of mass mortality incidents to work towards safeguarding these species and preserving their vital migration patterns.
... Starvation through inability to forage effectively has been pointed out as the main cause of mass mortality events of wintering seabirds during prolonged periods of severe weather in the North Atlantic Ocean (Clairbaux et al. 2021). These 'winter wrecks' disproportionally affect species relying on flapping flight, with alcids, cormorants and kittiwakes being the most abundant seabirds found dead in an emaciated condition (Harris and Wanless 1996, Gaston 2004, Morley et al. 2016). In the North Atlantic, the highest exposure of seabirds to cyclones occurs in the western part of the oceanic basin (Clairbaux et al. 2021), directly overlapping with the core of the kittiwake population range. ...
Article
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Understanding variation in animal distributions is a central and challenging question in ecology that has become particularly critical in the context of global environmental changes. While distributions are often studied for resident or breeding species, species range limits are equally important for migratory species in winter when population regulation may occur due to limited resources in the non‐breeding season. A central hypothesis in several theories is that the density, fitness and performance of individuals decrease towards the edge of the range as organisms become maladapted when approaching the limit of their environmental tolerance (‘abundant centre hypothesis'). Energy is a critical resource, especially in winter when environmental conditions deteriorate, and this hypothesis predicts that high energy expenditure (low performance) at the range limit would lead to rapidly dwindling body mass and reduced fitness. We investigated this hypothesis in an Arctic‐breeding seabird wintering in the North Atlantic, the black‐legged kittiwake Rissa tridactyla. From 2008 to 2019, we tracked 117 adult kittiwakes (n = 176 tracks) with geolocation devices and saltwater immersion sensors to estimate the migratory strategies, time–activity budget and energy expenditure of individuals during winter, and estimated their reproductive success after their return to the colony during summer. Population density was indeed higher towards the centre of the range. However, contrary to the predictions, the energy expenditure of individuals was higher at the centre of the range and decreased towards the edge. In contrast, there were no spatial differences in the reproductive success of individuals wintering at the centre versus at the edge of their range. We conclude that performance and fitness did not increase towards the centre of the wintering range, implying that although resource acquisition was likely higher at the abundant centre, energy expenditure was also higher, so that individual fitness was constant across the winter range.
... This mass stranding event, observed on a larger scale along the coasts of Portugal and Spain, was primarily attributed to extreme weather . Mass strandings during migration can occur when birds face prolonged physical exertion (Trapletti-Lanti et al., 2024), leading to starvation, exhaustion, or drowning (Morley, et al., 2016), but can also be caused by entanglement in fishing nets (Costa, et al., 2019). ...
Technical Report
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Coastal inspections for beached birds allow the collection of information on the spatial and temporal distribution of strandings and evaluate the causes of mortality. The main goals of this work is to identify the potential threats that seabirds are subject to, understand the occurrence of a temporal pattern of strandings and identify the possible cause of strandings and death. Once a month, a 5.3 km transect was carried out to record all the beached animals on Barreta Island from May 2020 to July 2023, data were collected on species, condition and physical state, possible reason for the stranding/death, as well as environmental data. In the 36 days of coastal inspections carried out throughout the study period, 709 seabirds were recorded. Seabird strandings averaged between 3.4 and 4.1 birds/km, with peaks in spring (5.0 ± 4.8 birds/km) and summer (5.3 ± 5.6 birds/km). Autumn had the lowest stranding rates (0.6 ± 0.7 birds/km). The Yellow-legged gull (N = 409) was the most stranded species, especially in spring (3.9 ± 3.8 birds/km), where 68% of stranded birds were adults. The Lesser Black-backed gull (N = 90) had higher strandings in winter (0.9 ± 0.7 birds/km), while Audouin's gull (N = 89) peaked in summer (2.3 ± 3.3 birds/km), predominantly consisting of juvenile birds. Notably, both Atlantic Puffins and Razorbills exhibited an increase in strandings, culminating in a significant mass stranding event in the country during the winter of late 2022 to early 2023. In most cases (82%), the cause of death was unknown, as the state of decomposition was advanced in the majority of the birds found. For the remaining birds poor physical condition was evident in 15% of the strandings, with 3% of birds with evident malnutrition. Evidence of paretic syndrome was recorded in 8% of the cases, mainly affecting gulls. Signs of predation were registered in 6% of the stranded birds, but 80% of these records reported that the predation was post-mortem. Only in 6 birds the predation was considered to be the main cause of the stranding, being reported predation by cats and birds of prey. Around 1% of the individuals showed signs of bycatch in fishing gear, from which 1 Audouin’s gull caught in a sport fishing hook, 5 Yellow-legged gulls, 1 Lesser Black-backed gull and 1 Northern gannet with evidences of capture by fishing nets, and 1 Yellow-legged gull with evidence of capture by longlines.
... In many cases, reports are primarily opportunistic, either collected and reported by members of the public (Rowe and Plant 2015;Morley et al. 2016), or opportunistically gathered during other ongoing scientific research (e.g., during atsea research cruises; Baduini et al. 2001). While such data have high value as evidence of occurrence (i.e., Piatt et al. 2020;Jones et al. 2023), they are often lacking with regards to standardized survey protocol or effort control, which greatly hampers efforts to quantitatively bound event magnitude. ...
Article
Full-text available
Mass mortality events (MMEs) of seabirds are becoming more frequent as the global climate warms. Often documented via beached bird surveys, methods for estimating event-wide mortality are needed that can accommodate regional differences in carcass deposition and data quality/quantity. We develop a framework for estimating mortality from beached bird counts, extending existing approaches through the novel application of ocean circulation modeling to assess beaching likelihood. We applied our framework to the 2014/15 Cassin’s auklet (Ptychoramphus aleuticus) MME, which spread across three regions (central California, northern California-through-Washington, British Columbia) with varying data quality/quantity. Our best mortality estimate of ∼400 000 (estimates ranged from 265 000 to 700 000 depending on model uncertainty and extent) places this seabird MME as one of the largest on record. However, we caution that much uncertainty exists surrounding model parameterization and deposition in British Columbia where beached bird data were sparse. We suggest that the application of ocean circulation models, combined with process-based modeling of carcass persistence and detection, can improve estimates of MME magnitude.
... Although many strandings in coastal areas around the world end up as unsolved cases, scientists have no shortage of suspected causes, including bycatch, disease, poisoning, injuries, parasites, malnutrition and storms (e.g. Arbelo et al., 2013;Truchon et al., 2013;Morley et al., 2016;Louzao et al., 2019;Dudhat et al., 2022). ...
Article
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... The effects of air temperature on seabirds are best known from the breeding season, with air temperature influencing productivity and/or adult survival through direct or indirect mechanisms (Bukaciński & Bukacińska 2000, Oswald et al. 2008, Gaston & Elliott 2013, Indykie wicz 2015. The effects of rainfall and storminess on seabird demographic rates can operate both on productivity (Thompson & Furness 1991, Newell et al. 2015 and adult survival (Frederiksen et al. 2008, Morley et al. 2016. ...
Article
Estimating species’ vulnerability to climate change is a key challenge in conservation. Many seabird species are particularly sensitive to the negative effects of warming and are thus threatened by climate change. We projected seabird abundance in 2050 in Britain and Ireland, an internationally important region for seabirds, under climate change scenario RCP8.5. Our projections were based on fitted relationships between abundance and both climatic (air temperature, precipitation) and oceanographic (sea surface temperature, potential energy anomaly) variables, estimated using a Bayesian hurdle model with spatial random effects. The most consistent responses to environmental variables were negative relationships between species presence or abundance and breeding season maximum terrestrial air temperature. Although data and modelling issues meant that future projections could be made for only 15 of the 25 species and with low predictive power for spatial abundance, predictive power was high for spatial presence and moderate for temporal abundance change. Projections suggest that seabirds will generally fare poorly under climate change in Britain and Ireland, with 10 species projected to decline in abundance by 2050. Variable model fit and projection uncertainty limited confidence, which was generally greater for declines than for increases. Fulmar, puffin and Arctic tern were each projected to decline by over 70% with higher confidence. For a few species, colonisation of new areas may reduce projected losses, but this is potentially limited by low availability of suitable habitat. Projected abundance change was more negative for marine specialists than for generalists. Our findings highlight the vulnerability and conservation needs of seabirds in a changing climate.
... The three combined areas of the NE Atlantic (Celtic Sea, Bay of Biscay, Iberian Coast) are all high biodiversity areas with many habitats and marine species, including endangered and protected species like cetaceans (Laran et al., 2017;Spitz et al., 2018) and seabirds (Morley et al., 2016). The Celtic Sea and Bay of Biscay are often considered as a single ecosystem in modelling studies (Moullec et al., 2017). ...
Article
Full-text available
Available information and potential data gaps for non-fish marine organisms (cnidarians, crustaceans, echinoderms, molluscs, sponges, mammals, reptiles, and seabirds) covered by the global database SeaLifeBase were reviewed for eight marine ecosystems (Adriatic Sea, Aegean Sea, Baltic Sea, Bay of Biscay/Celtic Sea/Iberian Coast, Black Sea, North Sea, western Mediterranean Sea, Levantine Sea) across European Seas. The review of the SeaLifeBase dataset, which is based on published literature, analyzed information coverage for eight biological characteristics (diet, fecundity, maturity, length-weight relationships, spawning, growth, lifespan, and natural mortality). These characteristics are required for the development of ecosystem and ecological models to evaluate the status of marine resources and related fisheries. Our analyses revealed that information regarding these biological characteristics in the literature was far from complete across all studied areas. The level of available information was nonetheless reasonably good for sea turtles and moderate for marine mammals in some areas (Baltic Sea, Bay of Biscay/Celtic Sea/Iberian Coast, Black Sea, North Sea and western Mediterranean Sea). Further, seven of the areas have well-studied species in terms of information coverage for biological characteristics of some commercial species whereas threatened species are generally not well studied. Across areas, the most well-studied species are the cephalopod common cuttlefish (Sepia officinalis) and the crustacean Norway lobster (Nephrops norvegicus). Overall, the information gap is narrowest for length-weight relationships followed by growth and maturity, and widest for fecundity and natural mortality. Based on these insights, we provide recommendations to prioritize species with insufficient or missing biological data that are common across the studied marine ecosystems and to address data deficiencies.
Article
Climate change is regarded as a major threat to seabird populations globally. While the impacts on certain species are well-studied, the majority remain understudied, which may limit our understanding of the key mechanisms linking climate change to population dynamics. This information is important to identify vulnerable species and inform potential conservation responses. To address this gap, we reviewed literature on the impacts of climate change on the demography of 25 seabird species breeding in the UK and Republic of Ireland from relevant studies conducted within the wider North-East Atlantic. We found regional and species-specific variations in research effort, with the North Sea being the most studied area. The most frequently studied species were Common Guillemot Uria aalge (n = 35), Black-legged Kittiwake Rissa tridactyla (n = 29), and European Shag Gulosus aristotelis (n = 25). Breeding productivity and population abundance were the primary demographic parameters investigated. The North Atlantic Oscillation and Sea Surface Temperature were commonly used to describe climate influences, often linked to bottom-up mechanisms affecting demography through changes in prey availability. Breeding productivity was the most monitored demographic rate across species; this may lead to important mechanisms affecting other demographic rates, such as survival, being overlooked. Regional and species-specific disparities in research could bias the identification of key mechanisms. Despite these uncertainties, current literature highlights the importance of climate impacts through the food chain and severe storm events affecting seabirds. In response, climate change adaptation should prioritise management of fish stocks near breeding colonies and coastal management to protect vulnerable colonies from storm events.
Article
The movements of seabirds during the immature period generally remain poorly understood, primarily due to the challenges involved with tracking birds that do not regularly return to a nest. This knowledge gap prevents us from gaining a full understanding of the areas used by seabird populations. Here, we attempted to track the post-fledging movements of Atlantic Puffins Fratercula arctica from Skomer Island (Wales, UK), by deploying geolocators on chicks ready to leave the nest. Despite our very small return rate (just two loggers out of 54, recording 485 and 196 days of data after fledging, respectively), our results provide a first glimpse into the distribution and scale of movements of young Puffins after fledging. The young Puffins undertook movements comparable in scale to those of post-breeding adults, and there were considerable differences between the two individuals. New initiatives to track juvenile seabirds in much larger numbers will hopefully soon provide more insight into seabird post-fledging movements.
Article
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Animals can be flexible in their migration strategies, using several wintering sites or a variety of routes. The mechanisms promoting the development of these migratory patterns and their potential fitness consequences are poorly understood. Here, we address these questions by tracking the dispersive migration of a pelagic seabird, the Atlantic puffin Fratercula arctica, using over 100 complete migration tracks collected over 7 years, including repeated tracks of individuals for up to 6 consecutive years. Because puffins have high flight costs, dispersion may generate important variation in costs of migration. We investigate differences in activity budgets and energy expenditure between different strategies. We find that puffins visit a range of overwintering destinations, resulting in a diversity of migratory routes differing in energy expenditures; however, they show interindividual similarity in the timings and location of major movements. We consider 3 hypothetical mechanisms that could generate this pattern: 1) random dispersion; 2) sex segregation; and 3) intraspecific competition or differences in individual quality. First, we dismiss random dispersion because individuals show strong route fidelity between years. Second, we find that sex differences contribute to, but do not account fully for, the migratory variation observed. Third, we find significant differences in breeding success between overwintering destinations, which, together with differences in foraging levels between routes, suggest that birds of different quality may visit different destinations. Taken together, our results show that dispersive migration is a complex phenomenon that can be driven by multiple factors simultaneously and can shape a population’s fitness landscape.
Article
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Seabird mortality resulting from oil spills is generally assessed based on the number of birds lost at sea. Drift blocks we often employed to determine the loss at sea and because blocks do not sink, but seabird carcasses do, it is essential to determine accurate sinking rates of seabird carcasses to correctly interpret onshore drift block recoveries. To quantify sinking rates of seabird carcasses, to determine possible differences between oiled and unoiled birds, and to investigate the importance of scavenging, I conducted an experiment in St. John's, Newfoundland, Canada, with 54 intact, but previously frozen murres (Uria spp.), the most common victims in oil spills in the Northern Hemisphere. Birds were randomly assigned to clean, lightly oiled (25% of body oiled) or heavily oiled (50% body oiled) categories. Twelve birds of each oiling category were placed into a floating three-chambered wooden-framed pen. The remaining birds were placed in a mesh-screened pen on the wharf. After nine days, randomly assigned carcasses from the floating pen and all birds on land, were opened to simulate partial scavenging. After 19 days, all flesh and muscles were removed from remaining birds to simulate complete scavenging. Changes in the buoyancy of carcasses were determined daily by measuring the amount of added mass (in 5 g increments) necessary to sink them (Burger 1991, cited in Burger and Fry 1993). On average, carcasses remained afloat 8.2 ± 1.0 d (95% C.I. 6.2 - 10.3), with no difference between oiled and unoiled, either floating or on land. Carcasses on land retained buoyancy significantly longer and only 1 carcass sank with the 24 d period. Buoyancy loss was best described by a logistic time-dependent function. When carcasses were scavenged, buoyancy loss increased exponentially. Based on these results, it appears that backwash and subsequent sinking of stranded carcasses is likely not a significant mechanism of carcasses removal from beaches. I recommend using a 10-14 d estimate for the length of time that murres and other auks remain afloat at sea, and to use a time-dependent logistic function to estimate the proportion of birds lost at sea. It appears that most estimates of seabird mortality due to spilled oil based on drift block experiments may be too low because onshore block recoveries relevant to seabird carcasses have been over-estimated.
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Download from: http://jncc.defra.gov.uk/page-2407#download This major atlas presents a comprehensive assessment of seabirds in north-west European waters and comes from a collaboration between several countries. Data were collected from 1979 to 1994 and have been used to describe the seasonal distribution and abundance of over 50 species of seabird, including: gulls; terns; sea ducks; skuas and divers. These are supplemented with detailed summaries of the methods used for the collection, processing and interpretation of the data. The atlas has been published using data from the European Seabirds at Sea database with contributions from the following organisations: Joint Nature Conservation Committee (United Kingdom); Nederlands Instituut voor Onderzoek der Zee (the Netherlands); Ornis Consult (Denmark); National Institute for Coastal and Marine Management/RIKZ (the Netherlands); Nederlands Zeevogelgroep (the Netherlands); Instituut voor Bos- en Natuuronderzoek (the Netherlands); Instituut voor Natuur Behoud (Belgium); National Environmental Research Institute (Denmark); Norsk Institutt for Naturforskning (Norway); Vogelwarte Helgoland (Germany).
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