Biases and best approaches for assessing debris ingestion in sea turtles, with a case study in the Mediterranean

Casale, Paolo; Freggi, Daniela; Paduano, Valentina; Oliverio, Marco

doi:10.1016/j.marpolbul.2016.06.057

Cited by 69 publications

(46 citation statements)

References 65 publications

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“…Within and between stranding sites there are differences in turtle foraging ecology, life stages and proximity to human habitation (Bolten 2003, Rees et al 2010, and therefore they are exposed to different levels and types of potential entangling materials. Individual turtles therefore may not represent a homogeneous group in terms of entanglement occurrence within that population (Casale et al 2016). Additionally, recovered carcasses represent an unknown fraction of at-sea mortalities, with physical oceanography (e.g.…”

Section: Caveatsmentioning

confidence: 99%

“…However, examining reports of stranded animals represents a vital opportunity for research and can provide insights into the impacts of anthropogenic threats which would otherwise go undetected (Chaloupka et al 2008, Casale et al 2010. In addition, stranding information aids with the assessment of harder-to-access life stages, yielding key information on the risk to specific resident populations and contributing to building a worldwide perspective for conservation issues (Chaloupka et al 2008, Casale et al 2016. Indeed, this was the aim of our study: using stranding data from expert respondents to gain an initial indication of the estimated magnitude of this threat.…”

Section: Caveatsmentioning

confidence: 99%

See 1 more Smart Citation

A global review of marine turtle entanglement in anthropogenic debris: a baseline for further action

Duncan¹,

Botterell²,

Broderick³

et al. 2017

Endang. Species. Res.

122

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Section: Caveatsmentioning

confidence: 99%

Section: Caveatsmentioning

confidence: 99%

A global review of marine turtle entanglement in anthropogenic debris: a baseline for further action

Duncan¹,

Botterell²,

Broderick³

et al. 2017

Endang. Species. Res.

122

View full text Add to dashboard Cite

“…Marine turtles occupying coastal foraging habitats are at risk of adverse anthropogenic effects including fisheries bycatch, vessel collision, and entanglement in and ingestion of synthetic marine debris (Denkinger et al 2013, Wallace et al 2013b, Lewison et al 2014, Schuyler et al 2014, Nelms et al 2016. Marine turtles ingest synthetic marine debris inadvertently if mixed or attached to natural diet items, or if mistaken for natural prey or forage (Carr 1987, Hoarau et al 2014, Casale et al 2016. Ingested synthetic debris can accumulate and obstruct, harm, or cause inflammation of the digestive tract, leading to reduced digestive ability, reduced fitness, and even possible mortality (Bjorndal et al 1994, Casale et al 2016, Nelms et al 2016, Schuyler et al 2016.…”

Section: Introductionmentioning

confidence: 99%

“…Marine turtles ingest synthetic marine debris inadvertently if mixed or attached to natural diet items, or if mistaken for natural prey or forage (Carr 1987, Hoarau et al 2014, Casale et al 2016. Ingested synthetic debris can accumulate and obstruct, harm, or cause inflammation of the digestive tract, leading to reduced digestive ability, reduced fitness, and even possible mortality (Bjorndal et al 1994, Casale et al 2016, Nelms et al 2016, Schuyler et al 2016. Other lesser-known consequences of synthetic debris ingestion are dietary dilution (McCauley & Bjorndal 1999) and the sublethal effects of desorbed or leached organic contaminants from plastics (Moore 2008, Teuten et al 2009, Engler 2012, N elms et al 2016.…”

Section: Introductionmentioning

confidence: 99%

“…However, examinations of stranded turtles from coastal foraging grounds can be used to elucidate key threats to a foraging aggregation (Cha loupka et al 2008, Cole et al 2011, Koch et al 2013. For instance, Casale et al (2016) suggested that stranded turtles are a good representative of neritic coastal foragers, and thus can reveal important information on the threats and risks to resident populations (Chaloupka et al 2008). In turn, information derived from such studies can highlight specific population-level im pacts and inform future mitigation and conservation strategies (Crowder et al 1995, Wallace et al 2011, Casale et al 2016, Nelms et al 2016.…”

Section: Introductionmentioning

confidence: 99%

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Anthropogenic impacts on green turtles Chelonia mydas in New Zealand

Godoy¹,

Stockin²

2018

Endang. Species. Res.

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Conservation strategies to sustain endangered green turtle Chelonia mydas populations must categorise and mitigate a range of anthropogenic threats. This study provides first insights into some of the adverse effects of anthropogenic activities on green turtles at a foraging area in New Zealand. Gross necropsies were conducted on 35 immature and sub-adult green turtles that were stranded in northern New Zealand between 2007 and 2013. Results revealed 54% (n = 19) of individuals exhibited human-related trauma, and 63% of these (n = 12) had ingested synthetic marine debris. The predominant plastic items ingested were soft plastics (e.g. single-use food packaging, plastic bags), and white, clear or translucent items. No correlation was observed between curved carapace length and the volume or number of synthetic debris items ingested. Propeller strike injuries were identified in 26% (n = 5) of turtles exhibiting human-related effects, while 10% (n = 2) had evidence of incidental capture in recreational fishing activities. Importantly, within New Zealand waters, anthropogenic effects predominantly associated with plastic ingestion are impacting the green turtle aggregation, and may be an important contributory factor to the stranding of immature and sub-adult green turtles in this region. Consequently, the threats identified in this study should be considered when developing population-specific conservation strategies.

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Citizen science helps assessing spatio‐temporal distribution of sea turtles in foraging areas

Casale

Ciccocioppo

Vagnoli

et al. 2019

Aquatic Conservation

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Spatio‐temporal distribution is fundamental information for species of conservation concern, like sea turtles, that are threatened by anthropogenic activities at sea such as fishing. While coarse‐scale distribution information is available for several sea turtle populations, fine‐scale distribution informing on hot‐spot areas for spatial management is more difficult to obtain. Here a citizen science approach involving tourism boats was undertaken to investigate the spatio‐temporal distribution of the loggerhead sea turtle (Caretta caretta) in the Pelagie Archipelago, located in a major foraging area for this species in the Mediterranean and where high fishing‐induced mortality occurs. The study was designed to provide data of absence and total sampling effort, commonly under‐reported in citizen science studies, allowing comparison among zones and periods. This was complemented by reports from fishing vessels. Tourism boats reported 584 loggerhead turtle sightings during 1718 daily trips and fishing vessels reported 280 loggerhead turtles captured during 1040 fishing days. The results indicate a strong heterogeneous distribution in the Archipelago, with a low turtle occurrence around the main island, Lampedusa, where the highest human presence and activity occur. This may represent rare evidence of displacement behaviour of turtles that is worth further investigation. This also suggests that the current small marine protected area around Lampedusa has a low conservation impact. Zones with higher loggerhead turtle occurrence appear to be in the south and the west parts of the Archipelago, suggesting that spatial management would be possible when relatively small hot‐spots have been identified through specific surveys. This study shows the potential of citizen science for providing preliminary information to guide more demanding and specific investigations. Such an approach may tremendously and rapidly improve the current knowledge on fine‐scale sea turtle distribution in regions with a great extension of coastlines and intensive tourist activities, such as the Mediterranean.

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Biases and best approaches for assessing debris ingestion in sea turtles, with a case study in the Mediterranean

Cited by 69 publications

References 65 publications

A global review of marine turtle entanglement in anthropogenic debris: a baseline for further action

A global review of marine turtle entanglement in anthropogenic debris: a baseline for further action

Anthropogenic impacts on green turtles Chelonia mydas in New Zealand

Citizen science helps assessing spatio‐temporal distribution of sea turtles in foraging areas

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