Jaume Forcada, Author at British Antarctic Survey

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Jaume Forcada

Marine Mammal Scientist

Marine mammal expert and population biologist at BAS. Graduated at the University of Barcelona with a PhD on marine mammal population assessment. Research Associate at the NOAA Southwest Fisheries Science Center in La Jolla, CA (USA), before joining BAS.

I conducted field work and population assessments on marine mammals in the western Mediterranean, western Sahara, Eastern North Atlantic, North Sea, and Eastern Tropical Pacific. Since I joined BAS in 2002, I have spent 1006 days (2.76 years) over 15 different field seasons working on Antarctic fur seals, leopard seals, and elephant seals at Bird Island, South Georgia. I have also done a short field season in Svalbard, Ny Alesund, working on walruses.

Research interests

I research how a range of marine mammals and seabirds in the Southern Ocean respond and adapt to increasing environmental fluctuation. Key components of this research focus upon food web interactions (e.g. energetic requirements, prey preferences), life history and population responses (e.g. intrinsic and environmental impacts, individual effects, genotypes), regional density and ecological impact of key species (e.g. seals and resource consumption in areas managed for fisheries) and anthropogenic impacts (e.g. climate change effects on the physical habitat of marine predators).

My specific work focuses:

Empirical data analysis to evaluate population and demographic parameters
Life history, demographic and population modelling to evaluate individual and population responses to environmental variation
Analysis of phenotypic and genetic variation to asses the consequences of climate change
Assessment of environmental variation on population changes of marine predators and their prey.
Krill predator community dynamics in response to climate change

Collaborations

University of Bielefeld, Germany; Prof Joe Hoffman
Department of Animal Biology, Univeristy of Barcelona; Prof Alex Aguilar.

Botsidou P, Schloter M, Maraci Ö, Gschwendtner S, Nagel R, FORCADA J, Hoffman JI. 2025 (preprint) Skin but not gut microbial communities in Antarctic fur seals vary with social density. BioRxiv. doi: https://doi.org/10.1101/2025.03.19.644101

Berthelsen AL, Paijmans AJ, FORCADA J, Hoffman JI. 2025 (preprint) Sustainability in the laboratory: evaluating the reuseability of microtiter plates for PCR and fragment detection. BioRxiv. doi: https://doi.org/10.1101/2024.10.16.618673

Fretwell PT, Bamford C, Skachkova A, Trathan PT, FORCADA. 2025 (Accepted) A fifteen-year assessment of emperor penguin breeding populations from the Bellingshausen to Weddell Sea from VHR satellite imagery. Communications Earth & Environment.

Mills WF, Buss D, Bustamante P, Ramírez F, FORCADA J, Forero M, Phillips R. 2025 Annual trends in mercury contamination are associated with changing trophic niches of giant petrels. Environmental Research 270: 121010. https://doi.org/10.1016/j.envres.2025.121010

Bennison A, Adlard S, Banyard AC, Blockley F, Blyth M, Browne E, Day G, Dunn MJ, Falchieri M, Fitzcharles E, FORCADA J, Forster Davidson J, Fox A,
Hall R, Holmes E, Hughes K, James J, Lynton-Jenkins J, Marshall S, McKenzie D, Morley SA, Reid SM, Stubbs I, Ratcliffe N, Phillips RA (2024). A case study of highly pathogenic avian influenza (HPAI) H5N1 at Bird Island, South Georgia: the first documented outbreak in the subantarctic region. Bird Study, 1–12. https://doi.org/10.1080/00063657.2024.2396563

Hench K, Vendrami DLJ, FORCADA J, Hoffman JI (2024) Refinement of the Antarctic fur seal (Arctocephalus gazella) reference genome increases continuity and completeness, G3 Genes|Genomes|Genetics, 2024;, jkae179. https://doi.org/10.1093/g3journal/jkae179.

Nagel R, Pohle K, Jordán L, Tuponja I, Stainfield C, Toscani C, Fox‑Clarke C, Costantini D, Czirják G, FORCADA J, Hoffman J (2024) Life-history stage influences immune investment and oxidative stress in response to environmental heterogeneity in Antarctic fur seals. Communications Biology 7(1):788. https://doi.org/10.1038/s42003-024-06499-6.

Paijmans AJ, Berthelsen AL, Nagel R, Cristaller F, Kröcker N, FORCADA J, Hoffman JI. 2024. Little evidence of inbreeding depression for birth mass, survival and growth in Antarctic fur seal pups. Scientific Reports 14, Pg. 12610. https://www.nature.com/articles/s41598-024-62290-x

Cubaynes HC, FORCADA J, Kovacs KM, Lydersen C, Downie R, Fretwell PT. 2024. Walruses from Space: walrus counts in simultaneous remotely piloted aircraft system vs very high-resolution satellite imagery. Remote Sensing in Ecology and Conservation 10: 584-596. https://doi.org/10.1002/rse2.391

Tebbe J, Havenstein K, FORCADA J, Tiedemann R, Caspers B, Hoffman JI. 2024. No evidence for a role of MHC class II genotype in the chemical encoding of heterozygosity and relatedness in Antarctic fur seals. Proc. R. Soc. B 291: 20232519.https://doi.org/10.1098/rspb.2023.2519

Hill SL, Atkinson A, Arata JA, Belcher A, Bengtson Nash S, Bernard KS, Cleary A, Conroy JA, Driscoll R, Fielding S, Flores H, FORCADA J, Halfter S, Hinke JT, Hückstädt L, Johnston NM, Kane M, Kawaguchi S, Krafft BA, Krüger L, La HS, Liszka CM, Meyer B, Murphy EJ, Pakhomov EA, Perry F, Piñones A, Polito MJ, Reid K, Reiss C, Rombola E, Saunders RA, Schmidt K, Sylvester ZT, Takahashi A, Tarling GA, Trathan PN, Veytia D, Watters GM, Xavier JC, Yang G. 2024. Observing change in pelagic animals as sampling methods shift: the case of Antarctic krill. Frontiers in Marine Science 11. Article DOI:10.3389/fmars.2024.1307402. https://www.frontiersin.org/articles/10.3389/fmars.2024.1307402

FORCADA J, Hoffman JI, Gimenez O, Staniland IJ, Bucktrout P, Wood AG. 2023. Ninety years of change, from commercial extinction to recovery, range expansion and decline for Antarctic fur seals at South Georgia. Global Change Biology 29:6867-6887. Article DOI: 10.1111/gcb.16947. https://onlinelibrary.wiley.com/doi/full/10.1111/gcb.16947

Toro-Valdivieso C, Jugdaohsingh R, Powell JJ, Hoffman JI, FORCADA J, Moore C, Blacklaws B. 2023 Heavy metal contamination in pristine environments: lessons from the Juan Fernandez fur seal (Arctocephalus philippii philippii). R. Soc. Open Sci. 10: 221237. https://doi.org/10.1098/rsos.221237

Tebbe J, Ottensmann M, Havenstein K, Efstratiou A, Lenz TL, Caspers BA, FORCADA J, Tiedemann R, Hoffman JI. 2022. Intronic primers reveal unexpectedly high major histocompatibility complex diversity in Antarctic fur seals. Scientific Reports 12, 17933. https://doi.org/10.1038/s41598-022-21658-7

Stainfield C, FORCADA J. 2022. Leopard seal (Hydrurga leptonyx) immature male play behaviour. Aquatic Mammals 48:568-573. https://doi.org/10.1578/AM.48.6.2022.568

van der Linde, K, Visser IN, Bout R, Krause DJ, FORCADA J, Siniff D, Stone S, Fyfe J, Fernández-Ferrada N, Macallan K, Savenko O, Cooper TE. 2022. A review of leopard seal (Hydrurga leptonyx) births and pups using a standardised age-class classification system. Polar Biol (2022). https://doi.org/10.1007/s00300-022-03053-0

Nagel R, Coleman J, Stainfield C, FORCADA J, Hoffman JI. 2022. Observations of giant petrels (Macronectes sp.) attacking and killing Antarctic fur seal (Arctocephalus gazella) pups. Aquatic Mammals 2022, 48(6) DOI 10.1578/AM.48.6.2022.

Vendrami DLJ, Gossmann TI, Chakarov N, Paijmans AJ, Litzke V, Eyre-Walker A, FORCADA J., Hoffman JI. 2022. Signatures of Selection on Mitonuclear Integrated Genes Uncover Hidden Mitogenomic Variation in Fur Seals. Genome Biology and Evolution 14 (7) evac104. https://doi.org/10.1093/gbe/evac104.

Hoffman JI, Chen RS, Vendrami DLJ, Paijmans AJ, Dasmahapatra KK, FORCADA J (2022) Demographic reconstruction of Antarctic fur seals supports the krill surplus hypothesis. Genes 13:541. https://doi.org/10.3390/genes13030541

Nagel R, Kaiser S, Stainfield C, Toscani C, Fox-Clarke C, Paijmans A, Costa Castro C, Vendrami D, FORCADA J, Hoffman J (2022) Low heritability and high phenotypic plasticity of salivary cortisol in response to environmental heterogeneity in a wild pinniped. Ecology and Evolution 12: e8757 (pp1-13). http://dx.doi.org/10.1002/ece3.8757

Cleary AC, Hoffman JI, FORCADA J, Lowther AD, Lydersen C, Kovacs KM. (2021) 50,000 years of ice and seals: impacts of the Last Glacial Maximum on Antarctic fur seals. Ecology and Evolution 11:14003-14011. https://doi.org/10.1002/ece3.8104

Nagel R, Mews S, Adam T, Stainfield C, Fox-Clarke C, Toscani C, Langrock R, FORCADA J, Hoffman JI. 2021. Movement patterns and activity levels are shaped by the neonatal environment in Antarctic fur seal pups. Scientific Reports 1:14323. https://doi.org/10.1038/s41598-021-93253-1

Nagel R, Stainfield C, Fox-Clarke C, Toscani C, Forcada J, Hoffman JI. 2021. Evidence for an Allee effect in a declining fur seal population. Proceeding of the Royal Society B 288: 20202882. https://doi.org/10.1098/rspb.2020.2882

Tebbe J, Humble E, Stoffel MA, Tewes LJ, Müller C, Forcada J, Caspers B, Hoffman JI. 2020. Chemical patterns of colony membership and mother-offspring similarity in Antarctic fur seals are reproducible. PeerJ 8:e10131 https://doi.org/10.7717/peerj.10131

Humble E, Paijmans A, FORCADA J, Hoffman J. An 85K SNP array uncovers inbreeding and cryptic relatedness in an Antarctic fur seal breeding colony. 2020. G3: Genes, Genomes, Genetics 10:2787-2799. https://doi.org/10.1534/g3.120.401268

Peart CR, Tusso S, Pophaly SD, Botero-Castro F, Wu C, Aurioles-Gamboa D, Baird AB, Bickham JW, FORCADA J, Galimberti F, Gemmell NJ, Hoffman JI, Kovacs KM, Kunnasranta M, Lydersen C, Nyman T, de Oliviera LR, Orr AJ, Sanvito S, Valtonen M, Shafer ABA, Wolf JBW. 2020. Determinants of genetic variation across eco-evolutionary scales in pinnipeds. Nature Ecology and Evolution 4:1095-1104. https://doi.org/10.1038/s41559-020-1215-5

Humble E, Paijmans A, FORCADA J, Hoffman JI. (bioRxiv preprint) A 90K SNP array uncovers inbreeding and cryptic relatedness in an Antarctic fur seal breeding colony. doi: https://doi.org/10.1101/2020.04.01.020123.

Jones K, Ratcliffe N, Votier S, Newton, FORCADA J, Dickens J, Stowasser G, Staniland I. 2020. Intra-specific Niche Partitioning in Antarctic Fur Seals, Arctocephalus gazella. Scientific Reports 10:3238. https://doi.org/10.1038/s41598-020-59992-3.

Jones KA, Wood H, Ashburner JP, FORCADA J, Ratcliffe N, Votier SC, Staniland IJ. 2020. Risk exposure trade-offs in the ontogeny of sexual segregation in Antarctic fur seal pups. Behavioral Ecology. https://doi.org/10.1093/beheco/araa018.

Paijmans A, Stoffel M, Bester M, Cleary A, de Bruyn PJN, FORCADA J, Goebel M, Goldsworthy S, Guinet C, Lydersen C, Kovacs K, Lowther A, Hoffman J. 2020. The genetic legacy of extreme exploitation in a polar vertebrate. Scientific Reports 10, 5089. https://doi.org/10.1038/s41598-020-61560-8

Cubaynes HC, Rees W G, Jackson J A, Moore M, Sformo TL, McLellan WA, Niemeyer ME, George JC, van der Hoop J, FORCADA J, Trathan PN, Fretwell PT. 2020. Spectral reflectance of whale skin above the sea surface: a proposed measurement protocol. Remote Sensing in Ecology and Conservation. https://zslpublications.onlinelibrary.wiley.com/doi/full/10.1002/rse2.155

Cleary AC, Bester M, FORCADA J, Goebel M, Goldsworthy SD, Guinet C, Hoffman JI, Kovacs KM, Lydersen C, Lowther AD. 2019. Prey differences drive local genetic adaptation in Antarctic fur seals. Marine Ecology Progress Series 628:195-209. https://doi.org/10.3354/meps13108

Nagel R, FORCADA J, Hoffman JI (Accepted) Complete mitochondrial genome of the Antarctic fur seal (Arctocephalus gazella). Mitochondrial DNA Part B: Resources 4:2, 2936-2937, DOI 10.1080/23802359.2019.1662751. https://doi.org/10.1080/23802359.2019.1662751

Litzke V, Ottensmann M, FORCADA J, Heitzmann L, Hoffman JI. 2109. Heterozygosity at neutral and immune loci does not influence neonatal mortality due to microbial infection in Antarctic fur seals. Ecology and Evolution 00:1-12. https ://doi.org/10.1002/ece3.5317

Grosser S, Sauer J, Paijmans AJ, Caspers BA, FORCADA J, Wolf JBW, Hoffman JI. 2019. Fur seal microbiota are shaped by the social and physical environment, show mother-offspring similarities and are associated with host genetic quality. Molecular Ecology 28:2406-2422. https://doi.org/10.1111/mec.15070

Gianuca D, Votier SC, Pardo D, Wood AG, Sherley RB, Ireland L, Choquet R, Pradel R, Townley S, FORCADA J, Tuck GN, Phillips RA. 2019. (Online). Sex-specific effects of fisheries and climate on the demography of sexually dimorphic seabirds. Journal of Animal Ecology 88:1366–1378. https://doi.org/10.1111/1365-2656.13009

Vendrami DLJ, FORCADA J, Hoffman JI. 2019. Experimental validation of in silico predicted RAD locus frequencies using genomic resources and short read data from a model marine mammal. BMC Genomics 20:72 (1-12). https://doi.org/10.1186/s12864-019-5440-8

Hoffman J I, Bauer E, Paijmans A, Humble E, Beckmann L M, Kubetschek C , Christaller F, Kröcker N, Fuchs B, Moreras A, Shihlomule Y D, Bester M N, Cleary A C, De Bruyn P J N,
FORCADA J, Goebel M, Goldsworthy S D, Guinet C, Hoelzel A R, Lydersen C, Kovacs K M, Lowther A. A global cline in a colour polymorphism suggests a limited contribution of gene flow towards the recovery of a heavily exploited marine mammal. Royal Society Open Science 5: 181227. http://dx.doi.org/10.1098/rsos.181227

Dunn M J, FORCADA J, Jackson J A, Waluda C M, Nichol C, Trathan P N. 2018. A long-term study of gentoo penguin (Pygoscelis papua) population trends at a major Antarctic tourist site, Goudier Island, Port Lockroy. Biodiversity and Conservation. https://doi.org/10.1007/s10531-018-1635-6

Humble E, Dasmahapatra K, Martinez-Barrio A, Gregorio I, FORCADA J, Polikeit A-C, Goldsworthy S, Goebel M, Kalinowski J, Wolf J, Hoffman J. 2018. RAD sequencing and a hybrid Antarctic fur seal genome assembly reveal rapidly decaying linkage disequilibrium, global population structure and evidence for inbreeding. G3: Genes, Genomes, Genetics 8:2709-2722. https://doi.org/10.1534/g3.118.200171.

Staniland I J, Ratcliffe N, Trathan P N, FORCADA J. 2018. Long term movements and activity patterns of an Antarctic marine apex predator: The leopard seal. PLOS ONE 13(6): e0197767. https://doi.org/10.1371/journal.pone.0197767

Silber G K, Lettrich M, Thomas P O, Baker J, Baumgartner M, Becker E A, Boveng P, Dick D M, Fiechter J, FORCADA J, Forney K A, Griffis R B, Hare J, Hobday A J, Howell D, Laidre K L, Mantua N, Quakenbush L, Santora J A, Stafford K, Spencer P, Stock C, Sydeman W, Van Houtan K, Waples R S. 2017. Projecting Marine Mammal Distribution in a Changing Climate. Frontiers Marine Science 4:413. doi: 10.3389/fmars.2017.00413.https://doi.org/10.3389/fmars.2017.00413

Humble E, Thorne M A S, FORCADA J, Hoffman J I. 2016. Transcriptomic SNP discovery for custom genotyping arrays: impacts of sequence data, SNP calling method and genotyping technology on the probability of validation success. BMC Research Notes 9:418. 1-12. doi:10.1186/s13104-016-2209-x

Pardo D, FORCADA J, Wood A G, Tuck G N, Ireland L, Pradel R, Croxall J P, Phillips R A. 2017. Additive effects of climate and fisheries drive ongoing declines in multiple albatross species PNAS 2017 114 (50) E10829–E10837; published ahead of print November 20, 2017, doi:10.1073/pnas.1618819114. http://www.pnas.org/content/114/50/E10829.full.pdf?with-ds=yes

Peters L, Humble E, Kröcker N, Fuchs B, FORCADA J, Hoffman J I. 2016. Born blonde: a recessive loss of function mutation in the melanocortin 1 receptor is associated with cream coat colouration in Antarctic fur seals. Ecology and Evolution 6: 5705-5717. Doi: 10.1002/ece3.2290.

Humble E, Martinez-Barrio A, FORCADA J, Trathan P, Thorne M, Hoffmann M, Wolf J, Hoffman J. 2016. A draft fur seal genome provides insights into factors affecting SNP validation and how to mitigate them. Molecular Ecology Resources 16: 909:921. DOI:10.1111/1755-0998.12502.

Meise K, von Engelhardt N, FORCADA J, Hoffman JI. 2016. Offspring hormones reflect the maternal prenatal social environment: potential for foetal programming? PLoS ONE 11(1): e0145352. doi:10.1371/journal.pone.0145352

Chemical fingerprints encode mother-offspring similarity, colony membership, relatedness and genetic quality in fur seals. (2015) Stoffel, M A, Caspers B A, FORCADA J, Giannakara A, Baier MC, Eberhart-Phillips L J, Müller C, Hoffman J I. PNAS 112(3):E5005–E5012. doi: 10.1073/pnas.1506076112. http://www.pnas.org/content/112/36/E5005.short

Southwell D, Emerson L, FORCADA J, Southwell C. 2015. A bioenergetics model for estimating prey consumption by an Adélie penguin population in East Antarctica. Marine Ecology Progress Series 526:183-197. doi: 10.3354/meps11182.http://www.int-res.com/abstracts/meps/v526/p183-197/

FORCADA J, Hoffman JI. 2014. Climate change selects for heterozygosity in a declining fur seal population. NATURE 511:462-465. doi:10.1038/nature13542. http://www.nature.com/nature/journal/v511/n7510/full/nature13542.html

Horswill C, Matthiopoulos J, Green J A, Meredith M P, FORCADA J, Peat H, Preston M, Trathan P N, Ratcliffe N. 2014. Survival in macaroni penguins and the relative importance of different drivers; individual traits, predation pressure and environmental variability. Journal of Animal Ecology 83:1057-1067. doi:10.1111/1365-2656.12229.

Fretwell PT, Staniland IJ, FORCADA J. 2014. Whales from space: counting southern right whales by satellite. PLoS ONE 9(2): e88655. doi:10.1371/journal.pone.0088655. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0088655

Abadi F, Barbraud C, Besson D, Bried J, Crochet P-A, Delord K, FORCADA J, Grosbois V, Phillips RA, Sagar P, Thompson P, Waugh S, Weimerskirch H; Wood AG, Gimenez O. (2014) Importance of accounting for phylogenetic dependence in multi-species mark-recapture studies. Ecological Modelling 273:236-241.http://dx.doi.org/10.1016/j.ecolmodel.2013.11.017

Bonin, CA, Goebel ME, FORCADA J, Burton RS, Hoffman JI. (2013) Unexpected genetic differentiation between recently recolonized populations of a long-lived and highly vagile marine mammal. Ecology and Evolution. doi:10.1002/ece3.732.

Jensen SK, Nymo IH, FORCADA J, Godfroid J, Hall A. (2013) Brucella antibody seroprevalence in Antarctic fur seal (Arctocephalus gazella), Weddell seal (Leptonychotes weddellii) and southern elephant seal (Mirounga leonina). Diseases of Aquatic Organisms 105:175-181. doi:10.3354/dao02633.

Hoffman JI, Thorne MAS, McEwing R, FORCADA J, Ogden R. (2013) Cross-amplification and validation of SNPs conserved over 44 million years between seals and dogs. PLoS ONE 8(7): e68365. doi:10.1371/journal.pone.0068365. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0068365

Gonzalvo J, FORCADA J, Grau E, Aguilar A. (2013) Strong site-fidelity increases vulnerability of common bottlenose dolphins Tursiops truncatus in a mass tourism destination in the western Mediterranean Sea. Journal of the Marine Biological Association of the United Kingdom. doi:10.1017/S0025315413000866.

Hoffman JI, Tucker R, Bridget SJ, Clark MS, FORCADA J, Slate J. (2012) Rates of assay success and genotyping error when single nucleotide polymorphism genotyping in non-model organisms: a case study in the Antarctic fur seal. Molecular Ecology Resources. doi: 10.1111/j.1755-0998.2012.03158.x

Jensen SK, Nymo IH, FORCADA J, Godfroid J, Hall A. (2012) Prevalence of Toxoplasma gondii antibodies in pinnipeds from Antarctica. Veterinary Record. doi: 10.1136/vr.100848 (in press).

FORCADA J, Trathan PN, Boveng PL, Boyd IL,Burns JM,Costa DP, Fedak M, Rogers TL, Southwell CJ (2012). Responses of Antarctic pack-ice seals to environmental change and increasing krill fishing. Biological Conservation 149:40-60. http://dx.doi.org/10.1016/j.biocon.2012.02.002

May-Collado LM, FORCADA J (2012) Small-scale estimation of relative abundance for the coastal spotted dolphins (Stenella attenuata) in Costa Rica: the effect of habitat and seasonality. Revista Biologia Tropical Vol. 60 (Suppl. 2) 133-142.

Southwell CJ, Bengtson J, Bester M, Blix AS, Bornemann H, Boveng PL, Cameron M, FORCADA J, Laake J, Nordøy E, Plötz J, Rogers TL, Southwell D, Steinhage D, Stewart B, Trathan (2012). A review of data on abundance, trends in abundance, habitat use and diet of ice-breeding seals in the Southern Ocean. CCAMLR Science 19:49-74. http://www.ccamlr.org/en/system/files/science_journal_papers/Southwell-et-al.pdf

Hoffman J I, FORCADA J (2012) Extreme natal philopatry in female Antarctic fur seals (Arctocephalus gazella) Mammalian Biology 77:71-73.

Gómez-Campos E, Borrell A, Cardona L, FORCADA J, Aguilar A. (2011). Overfishing of Small Pelagic Fishes Increases Trophic Overlap between Immature and Mature Striped Dolphins in the Mediterranean Sea. PLoS ONE 6(9): e24554. doi:10.1371/journal.pone.0024554

Hoffman J I, Grant S M, FORCADA J, Phillips C D (2011) Bayesian inference of a historical bottleneck in a heavily exploited marine mammal. Molecular Ecology.20, 3989–4008. doi: 10.1111/j.1365-294X.2011.05248.x.

Staniland I J, Morton A, Robinson S L, Malone D, and FORCADA J. (2011) Investigating differing population recoveries: Contrasting the foraging behaviour of Antarctic fur seals between two colonies. Marine Ecology Progress Series 434:183-196.

Catry P, FORCADA J, Almeida A (2011). Demographic parameters of black-browed albatrosses Thalassarche melanophris from the Falkland Islands. Polar Biology 34:1221-1229. doi: 10.1007/s00300-011-0984-3.

Nevoux M, FORCADA J, Barbraud C, Croxall J P, Weimerskirch H (2010). Bet-hedging response to environmental variability, an intra-specific comparison. Ecology 91:2416-2427. doi: 10.1890/09-0143.1.

Hoffman J I, FORCADA J, Amos W (2010) Exploring the mechanisms underlying an heterozygosity-fitness correlation fopr canine size in the Antarctic fur seal Arctocephalus gazella. Journal of Heredity 101:539-552. doi:10.1093/jhered/esq046.

Hoffman J I, Hanson N, FORCADA J, Trathan P N, Amos W (2010) Getting long in the tooth: a strong positive correlation between canine size and heterozygosity in Antarctic fur seals Arctocephalus gazella. Journal of Heredity 101:527-538. doi:10.1093/jhered/esq045.

Hill S L, FORCADA J, Trathan P N, Waluda C M (2010) Using ecosystem monitoring data to detect impacts. CCAMLR Science 17:197-212.

Beekmans B W P M, FORCADA J, Murphy E J, de Baar H J W, Bathmann U V, Fleming A H (2010) Generalised additive models to investigate environmental drivers of Antarctic minke whale (Balaenoptera bonaerensis) spatial density in austral summer. Journal of Cetacean Research and Management 11:115-129.

FORCADA J, Malone D, Royle J A, Staniland I J (2009). Modelling predation by transient leopard seals for an ecosystem-based management of Southern Ocean fisheries. Ecological Modelling 220:1513-1521. doi:10.1016/j.ecolmodel.2009.03.020.

FORCADA J, Trathan P N. (2009). Penguin responses to climate change in the Southern Ocean. Global Change Biology 15:1618-1630, doi: 10.1111/j.1365-2486.2009.01909.x.

Edwards E W J, FORCADA J, Crossin G T (2009). First documentation of leopard seal predation of South Georgia pintail duck. Polar Biology, doi:10.1007/s00300-009-0709-z.

Hoffman J, FORCADA J (2009). Genetic analysis of twinning. Journal of Mammalogy 90:621-628.

FORCADA J, Trathan P N, Murphy E J. (2008). Life history buffering in Antarctic mammals and birds against changing patterns of climate and environmental variation. Global Change Biology 14:2473-2488. doi: 10.1111/j.1365-2486.2008.01678.x.

Trathan P N, FORCADA J, Atkinson R, Downie R H, Shears J R. (2008). Population assessments of gentoo penguins (Pygoscelis papua) breeding at an important Antarctic tourist site, Goudier Island, Port Lockroy, Palmer Archipelago, Antarctica. Biological Conservation 141:3019-3028.

Barbraud C, Weimerskirch H, Bost C-A, FORCADA J, Trathan P, Ainley D. 2008. Are king penguin populations threatened by Southern Ocean warming? Proceedings of the National Academy of Sciences 105:E38; doi:10.1073/pnas.0802013105.

Murphy E J, Trathan P N , Watkins J L , Reid K, Meredith M P, FORCADA J, Thorpe S E, Johnston N M and Rothery P. 2007. Climatically-driven fluctuations in Southern Ocean ecosystems. Proceedings of the Royal Society B. DOI:10.1098/rspb.2007.1180

Hoffman J L, FORCADA J, Trathan P N, Amos A. 2007. Female fur seals show active choice for males that are heterozygous and unrelated. NATURE 445:912-914. doi:10.1038/nature05558.

Aguilar A, Cappozzo L H, Gazo M, Pastor T, FORCADA J and Grau E. 2007. Lactation and mother–pup behaviour in the Mediterranean monk seal Monachus monachus: an unusual pattern for a phocid. Journal of the Marine Biological Association UK 87:93-99.

Trathan P N, FORCADA J, Murphy E J. 2007. Environmental forcing and Southern Ocean marine predator populations: effects of climate change and variability. Philosophical Transactions of the Royal Society B 362:2352-2365; doi:10.1098/rstb.2006.1953

Murphy E J, Watkins J L, Trathan P N, Reid K, Meredith M P, Thorpe S E, Johnston N M, Clarke A, Tarling G A, Collins M A, FORCADA J, Shreeve R S, Atkinson A, Korb R, Whitehouse M J, Ward P, Rodhouse P G, Enderlein P, Hirst A G, Martin A R, Hill S L, Staniland I J, Pond D W, Briggs D R, Cunningham N J and Fleming A H. 2007. Spatial and temporal operation of the Scotia Sea ecosystem: a review of large-scale links in a krill centred food web. Philosophical Transactions of the Royal Society B 362:113–148. doi:10.1098/rstb.2006.1957.

FORCADA J and Robinson S L (2006) Population abundance, structure and turnover estimates for leopard seals during winter dispersal combining tagging and photo-identification data. Polar Biology 29:1052-1062. DOI 10.1007/s00300-006-0149-y

Hoffman J I, FORCADA J and Amos W (2006) No relationship between microsatellite variation and neonatal fitness in Antarctic fur seals Arctocephalus gazella. Molecular Ecology 15:1995-2006.

Catry P, Phillips R A, FORCADA J and Croxall J P (2006) Factors affecting the solution of a parental dilemma in albatrosses: at what age should chicks be left unattended? Animal Behaviour 72:383-391.

Tornero V, Borrell A, Aguilar A, FORCADA J, Lockyer C (2006) Organochlorine contaminant and retinoid levels in blubber of common dolphins (Delphinus delphis) off northwestern Spain. Environmental Pollution 140:312-321.

Warren N L, Trathan P N, FORCADA J, Fleming A and Jessopp M J (2006) Distribution of post-weaning Antarctic fur seal Arctocephalus gazella pups at South Georgia. Polar Biology 29:179-188

FORCADA J, Trathan P N, Reid K, Murphy E J and Croxall J P (2006) Contrasting population changes in sympatric penguin species in association with climate warming. Global Change Biology 12:411-423

FORCADA J, Trathan P N, Reid K, Murphy E J (2005) The effects of global climate variability in pup production of Antarctic fur seals. Ecology 86:2408-2417.

Gerrodette T and FORCADA J (2005) Non-recovery of two spotted and spinner dolphin populations in the eastern Tropical Pacific Ocean. Marine Ecology Progress Series 291:1-21 (FEATURE ARTICLE).

Reid K and FORCADA J (2005) Causes of offspring mortality in the Antarctic fur seal, Arctocephalus gazella: the interaction of density dependence and ecosystem variability. Canadian Journal of Zoology 83:604-609.

Tornero V, Borrell A, Aguilar A, Wells R S, FORCADA J, Rowles T K and Reijnders P J H (2005) Effects of organochlorine contaminants and individual biological traits on blubber retinoid concentrations in bottlenose dolphins (Tursiops truncatus). Journal of Environmental Monitoring 7:109-114.

Tornero V, Borrell A, FORCADA, J.and Aguilar A (2004) Tissue distribution of retinoids in common dolphins Delphinus delphis. Marine Ecology Progress Series 280:275-283.

FORCADA J, Gazo M, Aguilar A, Gonzalvo J and Fernandez-Contreras M (2004) Bottlenose dolphin abundance in the NW Mediterranean: addressing heterogeneity in distribution. Marine Ecology Progress Series 275:275-287.

Tornero V, Borrell A, FORCADA, J, Pubill E and Aguilar A (2004) Retinoid and lipid patterns in the blubber of common dolphins (Delphinus delphis): implications for monitoring vitamin A status. Comparative Biochemistry and Physiology Part B 137:391-400.

Jessopp M J, FORCADA J, Reid K, Trathan P N and Murphy E J (2004) Winter dispersal of leopard seals (Hydrurga leptonyx): environmental factors influencing demographics and seasonal abundance. Journal of Zoology (London) 263:251-258.

Barlow J, Gerrodette T and FORCADA J (2001) Factors affecting perpendicular sighting distances on shipboard line-transect surveys for cetaceans. Journal of Cetacean Research and Management 3:201-212.

Borrell A, Aguilar A, FORCADA J, Fernandez M, Aznar F J and Raga J A (2000) Varamiento de cetáceos en las costas españolas del Mediterráneo durante el período 1989-1992. Miscel.lània Zoològica 23(1): 53-69.

FORCADA J and Aguilar A (2000) Use of photographic identification in capture-recapture studies of Mediterranean monk seals. Marine Mammal Science 16:767-793.

FORCADA J (2000) Can population surveys show if the Mediterranean monk seal colony at Cap Blanc is declining in abundance? Journal of Applied Ecology 37:171-181.

FORCADA J, Hammond P S and Aguilar A (1999) Status of the Mediterranean monk seal Monachus monachus in the western Sahara and the implications of a mass mortality event. Marine Ecology Progress Series 188:249-261.

FORCADA J and Hammond P S (1998) Geographical variation in density and numbers of striped and common dolphins of the western Mediterranean. Journal of Sea Research 39:313-325.

FORCADA J, Aguilar A, Hammond P, Pastor X and Aguilar R (1996) Distribution and abundance of fin whales in the Western Mediterranean Sea during the summer. Journal of Zoology (London) 238: 23-34.

Goujon M, FORCADA J and Desportes G (1995) Fin whale abundance in the temperate waters of the Eastern North Atlantic. Reports of the International Whaling Commission 44: 287-290.

FORCADA J, Notarbartolo di Sciara G and Fabbri F (1995) Abundance of fin whales and striped dolphins summering in the Corso-Ligurian basin. Mammalia 59(1): 127-140.

FORCADA J, Aguilar A, Hammond P, Pastor X and Aguilar R (1994) Distribution and numbers of striped dolphins in the western Mediterranean Sea after the 1990 epizootic outbreak. Marine Mammal Science 10(2): 137-150.

Book Chapters:

FORCADA J (2021) Antarctic Fur Seal (Arctocephalus gazella, Peters 1875), In “Ecology and Conservation of Pinnipeds in Latin America” (G. Heckel, and Y. Schramm, eds). Springer, Cham. https://doi.org/10.1007/978-3-030-63177-2_4

FORCADA J (2018) Distribution, In “Encyclopedia of Marine Mammals” (Bernd Würsig, J.G.M. Thewissen, and Kit M. Kovacs, eds.), 3rd ed, pp. 259 – 262, Academic Press/Elsevier, San Diego, CA, USA.

FORCADA J, Staniland (2018) Antarctic fur seal Arctocephalus gazella, In “Encyclopedia of Marine Mammals” (Bernd Würsig, J.G.M. Thewissen, and Kit M. Kovacs, eds.), 3rd ed, pp. 25 – 27, Academic Press/Elsevier, San Diego, CA, USA.

Trathan P N, FORCADA J, Murphy E J (2012) Environmental forcing and Southern Ocean marine predator populations. In: Rogers, A. D., Johnston, N. M., Murphy, E. J., Clarke, A. eds. Antarctic Ecosystems: An Extreme Environment in a Changing World. Blackwell Publishing Ltd.

FORCADA J, Staniland I J. 2008. Antarctic fur seal. In: W. F. Perrin, Würsig, B., and Thewissen, H. G. M. eds., The Encyclopedia of Marine Mammals 2nd Edition. Academic Press-Elsevier.

FORCADA J. 2008 Distribution. In: W. F. Perrin, Würsig, B., and Thewissen, H. G. M. eds., The Encyclopedia of Marine Mammals 2nd Edition. Academic Press-Elsevier.

Gilmartin W G and FORCADA J (2008) Monk Seals (Monachus monachus, M. tropicalis, and M. schauinslandi). In: W. F. Perrin, Würsig, B., and Thewissen, H. G. M. eds., The Encyclopedia of Marine Mammals 2nd Edition. Academic Press-Elsevier.

FORCADA J. 2008. The Impact of Climate Change on Antarctic Megafauna. Impacts of Global Warming on Polar Ecosystems (ed Carlos M Duarte), pp. 83-108. Fundación BBVA, Madrid.

FORCADA J. 2007. El cambio climático y sus repercusiones para la megafauna antártica. Impactos del calentamiento global sobre los ecosistemas polares (ed Carlos M Duarte), pp. 83-110. Fundación BBVA, Madrid.

Trathan P N, Murphy E J, FORCADA J, Croxall J P, Reid K, Thorpe S E (2006) Physical forcing in the southwest Atlantic: ecosystem control. In Boyd I L, Wanless S, Camphuysen C J (eds) Top predators in Marine Ecosystems. Cambridge University Press, Cambridge, p 28-45.

Gazo M, FORCADA J, Aguilar A, Fernandez-Contreras M, Borrell A, Gonzalvo J and Tornero V (2004) Sector Norte (Cataluña e islas Baleares). In Raga J A, Pantoja J (eds) Proyecto Mediterraneo. Zonas de especial interes para la conservacion de los cetaceos en el Mediterraneo Español. Ministerio de Medio Ambiente, Naturaleza y Parques Nacionales, Serie Tecnica. Madrid, Spain, p 15-64.

Gilmartin W G and FORCADA J (2002) Monk Seals (Monachus monachus, M. tropicalis, and M. schauinslandi). In: W. F. Perrin, Würsig, B., and Thewissen, H. G. M. eds., The Encyclopedia of Marine Mammals. Academic Press.

FORCADA J (2002) Distribution. In: W. F. Perrin, Würsig, B., and Thewissen, H. G. M. eds., The Encyclopedia of Marine Mammals. Academic Press.

Aguilar A, FORCADA J, Gazo M and Badosa E (1997) Los cetáceos del Parque Nacional de Coiba. A: Flora y fauna del Parque Nacional de Coiba (Panamá). Agencia Española de Coperación Internacional, Madrid, Spain.

Aguilar A, Grau E, Borrell A, Calzada N and FORCADA J (1995) Dofí llistat, Stenella coeruleoalba. In: Els Grans Mamífers de Catalunya i Andorra. Coordinadors: Jordi Ruiz-Olmo and Alex Aguilar. Edicions Lynx, Barcelona, Spain.

Beaubrun P, Bayed A, Bompar J M, Boutiba Z, FORCADA J, Gannier A, Giordano A, Maigret J, Notarbartolo di Sciara G, Ozturk B and Ripoll T H (1995) Atlas préliminaire de distribution des cétacés de Méditerranée. Commission lnternationale pour I’Explotation Scientifique de la mer Méditerranée. Musée Océanographique, Monaco, France.

Technical Reports:

Silber G K, Lettrich M, Thomas P O, Baker J, Baumgartner M, Becker E A, Boveng P, Dick D, Fiechter J, FORCADA J, Forney K A, Griffis R, Hare J, Hobday A, Howell D, Laidre K, Mantua N, Quakenbush L, Santora J, Spencer P, Stock C, Stafford K, Sydeman W, Van Houtan K, Waples R. 2016. Report of a Workshop on Best Approaches and Needs for Projecting Marine Mammal Distributions in a Changing Climate. NOAA Technical Memorandum NMFS-OPR-54. http://www.nmfs.noaa.gov/pr/publications/techmemos.htm

Forcada, J. 2002. Multivariate methods for size-dependent detection in conventional line transect sampling. SWFSC Admin. Rep., La Jolla, LJ-02-07, 35 p. http://swfsc.nmfs.noaa.gov/IDCPA/TunaDol_rep/LJ_02_07.pdf

Gerrodette, T., and J. Forcada. 2002. Estimates of abundance of northeastern offshore spotted, coastal spotted, and eastern spinner dolphins in the eastern tropical Pacific Ocean. SWFSC Admin. Rep., La Jolla, LJ-02-06, 43 p. http://swfsc.nmfs.noaa.gov/IDCPA/TunaDol_rep/LJ_02_06.pdf

Gerrodette, T., and J. Forcada. 2002. Estimates of abundance of striped and common dolphins, and pilot, sperm and Bryde’s whales in the eastern tropical Pacific Ocean. SWFSC Admin. Rep., La Jolla, LJ-02-20, 24 p. http://swfsc.nmfs.noaa.gov/IDCPA/TunaDol_rep/LJ_02_20.pdf

Gerrodette, T., Watters, G. and Forcada, J. 2005. Preliminary estimates of 2003 dolphin abundance in the eastern tropical Pacific. SWFSC Admin. Rep., La Jolla, http://swfsc.nmfs.noaa.gov.

Conference Proceedings:

FORCADA, J., AGUILAR, A., EVANS, P.G.H. and PERRIN, W.F.1990. Distribution of Common and striped dolphins in the temperate waters of the Eastern North Atlantic. A: P.G.H. Evans, Aguilar, A and Smeenk, C. Ed: European Research on Cetaceans, 4: 64-66.

AGUILAR, R., PASTOR, X. and FORCADA, J. 1991. Results of the Greenpeace cetacean survey cruises during the Western Mediterranean striped dolphin epizootic. A: P.G.H. Evans. Ed: European research on cetaceans, 5: 18-21.

FORCADA J, Aguilar A, Hammond P, Pastor X and Aguilar R (1992) Striped dolphin abundance in the western Mediterranean basin after the 1990 epizootic. Pags.143-149. Proceedings of the Mediterranean Striped Dolphin Mortality International Workshop. Pastor, X. & Simmons, M. Ed. Greenpeace International. Mediterranean Sea Project. Palma de Mallorca.

FORCADA J, Aguilar A, Hammond P, Pastor X and Aguilar R (1992) Population estimate of striped dolphin inhabiting the Western Mediterranean sea. A: P.G.H. Evans. Ed: European Research on cetaceans, 6: 105-107.

FORCADA J, Aguilar A, Hammond P, Pastor X and Aguilar R (1994) Distribution and Abundance of fin whales in the Western Mediterranean Sea during the summer. A: P.G.H. Evans. Ed: European Research on Cetaceans, 7: 120-130.

Notarbartolo di Sciara G, FORCADA J, Acquarone M and Fabbri F (1994) Population estimates of fin whales and striped dolphins summering in the CorsoLigurian basin. A: P.G.H. Evans. Ed: European Research on Cetaceans, 7: 135-138.

FORCADA J, Aguilar A, Hammond P, Pastor X and Aguilar R (1995) Striped dolphin abundance in the north-western Mediterranean. A: P.G.H.Evans. Ed: European Research on Cetaceans, 8: 96-98.

Goujon M, FORCADA J and Desportes G (1995) Fin whale abundance in the eastern north Atlantic, estimated from the French program MICA-93 data. A: P.G.H. Evans. Ed: European Research on Cetaceans,8: 81-83.

FORCADA J (1995) Striped dolphin habitats in the north-western Mediterranean. A: P.G.H.Evans. Ed: European Research on Cetaceans, 8: 95.

FORCADA J (1996) Abundance of common and striped dolphins in the south-western Mediterranean. A: P.G.H.Evans. Ed: European Research on Cetaceans, 9: 153-155.

Cantos G, Samaranch R, Badosa E, Grau E, Forcada J and Aguilar (1997) Photo-identification catalogue of Mediterranean monk seals (Monachus monachus) from the western Sahara. P.G.H.Evans. Ed: European Research on Cetaceans, 11:300-301.

Aguilar A, FORCADA J, Arderiu A, Gazo M and Silvani L (1999) Status and conservation threats of small cetaceans in Spanish waters. P.G.H. Evans, J. Cruz and J. A. Raga Ed: European Research on Cetaceans, 13:75.

Gazo M, FORCADA J, Pastor T, Cantos G, Grau E and Aguilar A (1999) Status and conservation threats of small cetaceans in Spanish waters. P.G.H. Evans, J. Cruz and J. A. Raga Ed: European Research on Cetaceans, 13:377.

FORCADA J and Gerrodette T (2001) Improving abundance estimates from line transect surveys: modelling sighting conditions and school size distribution. P.G.H. Evans and E. O’Boyle Eds: European Research on Cetaceans, 15:420.

Publications from NERC Open Research Archive

Forcada, J., Dunn, M., & Waluda, C. (2025). Seasonal sea ice concentration at Signy Island, South Orkney Islands, 1982-2024 (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/0283c3e4-2164-4dfb-a066-0c49b816d7b6
Fretwell, P., Bamford, C., Skachkova, A., Trathan, P., & Forcada, J. (2025). Model input and output statistics on fifteen-year assessment of emperor penguin breeding populations from the Bellingshausen sea to the Weddell sea from VHR satellite imagery, 2009-2023 (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/c8d8ffe6-0aff-493c-b40f-e63f0c35f081
Forcada, J. (2021). Counts of Antarctic fur seals from the special study beach at Bird Island South Georgia, from 1984 to 2019 (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/97acea13-b93d-4f3a-9cc7-f32e8df86cc0
Forcada, J. (2021). Antarctic Fur seal pup weight at Bird Island, South Georgia, from 1973 to 2020 (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/692fb625-ea99-4896-8354-b4da490535bb
Dunn, M., Nichol, C., Forcada, J., & Trathan, P. (2020). Population numbers and breeding success of Gentoo penguins (Pygoscelis papua) at Port Lockroy, Goudier Island, 1996 – 2020 (Version 1.0) [Data set]. UK Polar Data Centre, Natural Environment Research Council, UK Research & Innovation. https://doi.org/10.5285/92e92c14-0ff2-4ce2-8305-83d5b3a4071d
Staniland, I., Waluda, C., & Forcada, J. (2020). Platform Transmitting Terminal (PTT) tracking of Antarctic Fur Seals at Bird Island, South Georgia, from 1995 – 2010 (Version 1.0) [Data set]. UK Polar Data Centre, Natural Environment Research Council, UK Research & Innovation. https://doi.org/10.5285/224003cc-8f77-4980-8cac-5574e179e4f8

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International Advisory Panel Memeber, New Zealand Journal of Zoology
Associate editor (April 2012 to September 2024), Marine Mammal Science
Member, NERC Special Committee on Seals 2013 - 2017
Member, SCAR Expert Group On Seals
Member, IUCN - Species Survival Commission and Pinniped Specialist Group - 2020 ->

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