Content of harbour seal (Phoca vitulina) and grey seal (Halichoerus grypus) scats in prey classified by functional groups (samples collected in the baie de Somme, France, from 2002 to 2019)

Date 2020-11-04
Temporal extent 2002 -2019
Author(s) Planque YannORCID1, Vincent CécileORCID1, Caurant Florence1, 2, Spitz JérômeORCID1, 2
Affiliation(s) 1 : Centre d’Etudes Biologique de Chizé, UMR 7372 CNRS / La Rochelle Université, 5 allée de l'Océan, 17000 La Rochelle, France
2 : Observatoire PELAGIS, UMS 3462 CNRS / La Rochelle Université, 5 allée de l'Océan, 17000 La Rochelle, France
DOI 10.17882/76780
Publisher SEANOE
Note The dataset consists of a table summarising the content of seal scats (rows) in reconstructed body mass of prey (g) in six different functional groups (small benthic flatfish, large benthic flatfish, benthic non-flatfish, demersal fish, pelagic fish and pelagic squids). Prey species included in each functional group are given in the metadata file.
Keyword(s) Foraging ecology, Trophic, Marine mammals, Pinnipeds, Diet, Scat content, Faeces, Hard remains, Diagnostic hard parts, Fish otolith, Cephalopod beak, Harbour seals, Grey seals, Eastern English Channel, baie de Somme
Abstract

Harbour (Phoca vitulina) and grey seal (Halichoerus grypus) scat samples were collected in the baie de Somme, France, from 2002 to 2019 to identify the diet of both species. Diet analysis followed a procedure usually used for pinnipeds (e.g. Ridoux et al. 2007, https://doi.org/10.1017/S002531540705463X; Spitz et al. 2015, https://doi.org/10.1051/alr/2015001). Scats were washed in order to analyse their content in diagnostic hard prey remains (e.g. fish otoliths, fish bones and cephalopod beaks), and therefore to identify prey species consumed by seals. Key measurements on fish otoliths or cephalopod beaks were used to estimate body mass and length of prey consumed by seals (use of allometric relationships), and ultimately reconstruct seals’ diet content in mass (g). The content of seal scats are presented here in six functional groups of prey (small benthic flatfish with relative length < 200 mm, large benthic flatfish with relative length ≥ 200 mm, benthic non-flatfish, demersal fish, pelagic fish and pelagic squids).

Licence CC-BY-NC
Acknowledgments We thank participants who took part in the fieldwork collecting seal scats and who are from Picardie Nature, Parc naturel marin des estuaires picards et de la mer d’Opale (Office Français de la Biodiversité, OFB), and Association Découverte Nature, or who involved independently. We also thank interns (Andrea Kabumbu Bakaji, Emma Lebrault, Alice Blanchard, Alice Riti, Katie Besson, Zoé Provost, Bruno Dubief, Marie-Hélène Picard and Lucien You) and technicians at the Observatoire Pelagis and CEBC who took part in laboratory analyses. We thank Vanessa Becquet of Littoral, Environment and Societies (LIENSs) laboratory (UMR 7266, CNRS / La Rochelle Université) for access to the Molecular Core Facility of La Rochelle Université and help for DNA analyses to assign the seal species that produced scats. The analysis of harbour seal scats from 2002 to 2015 was funded by Région Picardie, Conseil général de la Somme and La Rochelle Université. The analysis of all grey seal scats and most recent harbour seal ones was performed through the “Eco-Phoques” project (2015–2018) funded by Région Hauts-de-France and Parc naturel marin des estuaires picards et de la mer d’Opale. Data are archived here as part of Yann Planque’s PhD project funded by La Rochelle Université and by the French Ministry of Higher Education, Research and Innovation.
Sensor metadata

Sample_type = Type of sample collected (here seal scat)

Num_collection = Sample ID

Species = Seal species that produced the scat. Pv = Harbour seal (Phoca vitulina); Hg = Grey seal (Halichoerus grypus). Assigned by DNA analysis, cf method in Spitz et al. (2015), https://doi.org/10.1051/alr/2015001

Collecting_site = Collecting site (here baie de Somme, France)

Date = Date the sample was collected in the field

Small_benthic_flatfish = Reconstructed mass (g) of small benthic flatfish (i.e. with relative length < 200 mm). It includes: Pleuronectes platessa, Platttichthys flesus, Solea solea, Pegusa lascaris, Buglossidium luteum, Microchirus variegatus, Und. Bothidea, Scophtalmus spp., Phrynorhombus norvegicus

Large_benthic_flatfish = Reconstructed mass (g) of large benthic flatfish (i.e. with relative length ≥ 200 mm). It includes: Pleuronectes platessa, Platttichthys flesus, Solea solea, Pegusa lascaris, Buglossidium luteum, Microchirus variegatus, Und. Bothidea, Scophtalmus spp., Phrynorhombus norvegicus

Benthic_non_flatfish = Reconstructed mass (g) of benthic non-flatfish. It includes: Und. Gobidae, Trachinus draco, Callionymus lyra, Und. Triglidae

Demersal_fish = Reconstructed mass (g) of demersal fish. It includes: Merlangius merlangus, Trisopterus spp., Gadus morhua, Pollachius spp., Melanogrammus aeglefinus, Und. Sandeels, Dicentrarchus labrax, Und. Mullets

Pelagic_fish = Reconstructed mass (g) of pelagic fish. It includes: Clupea harengus, Sardina pilchardus, Sprattus sprattus, Belone belone, Trachurus trachurus

Pelagic_squids = Reconstructed mass (g) of pelagic squids. It includes: Loligo spp.

[Und.: undetermined species]

Data
File Size Format Processing Access
Data 21 KB CSV Quality controlled data Open access
Metadata 1 KB CSV Quality controlled data Open access
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How to cite 

Planque Yann, Vincent Cécile, Caurant Florence, Spitz Jérôme (2020). Content of harbour seal (Phoca vitulina) and grey seal (Halichoerus grypus) scats in prey classified by functional groups (samples collected in the baie de Somme, France, from 2002 to 2019). SEANOE. https://doi.org/10.17882/76780