Delphinus Delphis Gulf of Corinth Subpopulation, Common Dolphin

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The IUCN Red List of Threatened Species™ ISSN 2307-8235 (online) IUCN 2020: T156206333A170381113 Scope(s): Global Language: English

Delphinus delphis Gulf of Corinth subpopulation, Common Dolphin

Assessment by: Bearzi, G., Bonizzoni, S. & Santostasi, N.

View on www.iucnredlist.org

Citation: Bearzi, G., Bonizzoni, S. & Santostasi, N. 2020. Delphinus delphis(Gulf of Corinth subpopulation). The IUCN Red List of Threatened Species 2020: e.T156206333A170381113. https://dx.doi.org/10.2305/IUCN.UK.2020-2.RLTS.T156206333A170381113.en

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THE IUCN RED LIST OF THREATENED SPECIES™ Taxonomy

Kingdom Phylum Class Order Family

Animalia Chordata Mammalia Cetartiodactyla Delphinidae

Scientific Name: Delphinus delphis Gulf of Corinth subpopulation Linnaeus, 1758

Parent Species: See Delphinus delphis

Common Name(s): • English: Common Dolphin • French: Dauphin commun • Spanish; Castilian: Delfin Comun • Albanian: Delfin i zakonshem عئاشلا نيفلدلا ,Arabic: Al-dolpheen Al-sha'eh • • Greek, Modern Kino delfini, Κοινό δελφίνι (1453-): יוצמ ןיפלוד ,Hebrew: Dolphin matzuy • • Italian: Delfino comune • Slovenian: Navadni delfin • Turkish: Tırtak Taxonomic Notes: This is a subpopulation of the Common Dolphin, Delphinus delphis Linnaeus, 1758. See also the global assessment for this species (Hammond et al. 2008) and the assessment of the Mediterranean Sea subpopulation (Bearzi 2003). Assessment Information

Red List Category & Criteria: Critically Endangered D ver 3.1

Year Published: 2020

Date Assessed: June 16, 2019

Justification: Fewer than 50 mature individuals exist within this subpopulation. The Common Dolphin Gulf of Corinth subpopulation was estimated to contain an average of 22 (95% CI 16–32) individuals (Santostasi et al. 2016). Even assuming an upper CI limit and 100% being mature individuals (i.e. complete absence of immatures), the abundance of mature individuals would be well below the threshold for classifying this subpopulation as Critically Endangered under criterion D (number mature < 50). As the Common Dolphin Gulf of Corinth subpopulation is isolated from conspecifics (Bearzi et al. 2016), the assessment must be based on unaltered IUCN Red List criteria (Gärdenfors et al. 2001). When assessing subpopulations, the occurrence and status of conspecific units that may affect the risk of extinction within the region should be considered (Taylor 2005). Common Dolphin are not known to occur in the adjacent Gulf of Patras. The closest area with quantitative information on abundance and trends is the Inner Ionian Sea archipelago, where Common Dolphins have declined dramatically (Bearzi et al. 2008, 2006; Piroddi et al. 2011). Therefore, based on the available information, it cannot be assumed that

© The IUCN Red List of Threatened Species: Delphinus delphis Gulf of Corinth subpopulation – published in 2020. 1 https://dx.doi.org/10.2305/IUCN.UK.2020-2.RLTS.T156206333A170381113.en Common Dolphins surviving in the eastern Ionian Sea may represent a ‘source’ population capable of having a ‘rescue effect’ on the Gulf of Corinth Common Dolphin subpopulation. Sharp declines also have been documented for the Adriatic Sea, with almost complete eradication of a species that was historically abundant (Bearzi et al. 2004). Geographic Range

Range Description: The Gulf of Corinth Common Dolphin subpopulation is confined to the central portion of the Gulf of Corinth, Greece, with no evidence of individuals ever crossing the narrow Strait of Rion which connects the Gulf of Corinth to open Mediterranean Sea waters (Frantzis et al. 2003, Bearzi et al. 2016), including across seven years (2011–2017) of intensive survey effort and tracking of dolphin movements (Bonizzoni et al. 2019; also see Figure 1 in the Supplementary Information).

Species distribution models based on seven years of intensive surveys (2011–2017; Bonizzoni et al. 2019) predicted a preferred habitat situated in the central/southern sector of the Gulf of Corinth, with hotspots of Common Dolphin distribution encompassing 512 km². The area of occupancy varied between 234 and 311 km² in years 2011–2015, while the total area of occupancy was 708 km2. The extent of occurrence varied between 448 and 651 km² in years 2011–2015. The total extent of occurrence was 1,014 km² (Santostasi et al. 2018).

For further information about this species, see Supplementary Material.

Country Occurrence: Native, Extant (resident): Greece

FAO Marine Fishing Areas: Native: Mediterranean and Black Sea

© The IUCN Red List of Threatened Species: Delphinus delphis Gulf of Corinth subpopulation – published in 2020. 2 https://dx.doi.org/10.2305/IUCN.UK.2020-2.RLTS.T156206333A170381113.en Population The Gulf of Corinth subpopulation was estimated as 22 Common Dolphins (95% CI 16–32) based on photographic capture-recapture covering the entire known range, conducted between 2011 and 2015 (Santostasi et al. 2016). The Gulf also hosts animals of intermediate Striped x Common Dolphin pigmentation (55 individuals, 95% CI 36–84; Santostasi et al. 2016), recently confirmed to be individuals with mixed ancestry (hereafter 'admixed'; Antoniou et al. 2018).

Common Dolphins occur in this gulf only in mixed-species groups with Striped Dolphins (Bonizzoni et al. 2019). Living exclusively within mixed-species groups with the 60-fold more abundant Striped Dolphins likely developed as an adaptation to low Common Dolphin numbers (Frantzis and Herzing 2002). While mixed-species groups may bring advantages to either species, Striped and Common Dolphins are closely related and inter-mating is known to occur in the Gulf of Corinth (Antoniou et al. 2018). The resulting hybridisation and introgression are significant threats for rare species coexisting with more abundant species (Allendorf et al. 2001, Levin 2002). Hybridisation may lead to the local eradication of a population due to genetic swamping (where ‘pure’ species are progressively replaced by hybrids), or demographic swamping (where population growth rates are reduced due to the expression of deleterious alleles and the production of maladaptive hybrids). In the Gulf of Corinth, the production of hybrid offspring (Antoniou et al. 2018) can negatively affect the status of Common Dolphins (Santostasi et al. 2018).

There is a clear population boundary between Common Dolphins occurring in the western and the eastern Mediterranean Sea, with additional differentiation in the Ionian Sea (Moura et al. 2013, Natoli et al. 2008). Geographic isolation of Common Dolphins in the Gulf of Corinth has been proposed based on absence of records in the western quarter of the Gulf and in the adjacent Gulf of Patras (Bearzi et al. 2011, Frantzis 2009, Frantzis et al. 2003), as well as consistent absence west of 22°08'30''E across seven years of intensive monitoring (Bearzi et al. 2016, Bonizzoni et al. 2019). Geographic isolation may have led to genetic differentiation, but information is scant. Genetic evidence from three Common Dolphins and 25 Striped Dolphins sampled in the Gulf of Corinth suggested significant differentiation for both species from individuals in the adjacent Ionian Sea and other Mediterranean areas (Gkafas 2011, Gkafas et al. 2007, Moura 2010, Moura et al. 2013).

Extinction probabilities were estimated by Santostasi et al. (2018). Based on a quasi-extinction threshold of two mature individuals and a constant growth rate, the subpopulation qualifies as Endangered based on criterion E. The introduction of environmental variability greatly increased the quasi-extinction probability, which becomes ≥0.5 and qualifies the Common Dolphin subpopulation as Critically Endangered based on criterion E. Regarding the expected abundance of mature individuals after three generations, for all the scenarios more than 90% of the projected abundance would fall in the interval 0–50 mature individuals, indicating that, even if the subpopulation does not go extinct, it will remain below the abundance threshold that qualifies it as Critically Endangered. The inclusion of temporal stochasticity led to a ≥ 50% probability of quasi-extinction in all scenarios. The effect of demographic stochasticity is likely present in the study subpopulation, given its small size. Therefore, the subpopulation may be also listed as Critically Endangered under criterion E. Current Population Trend: Unknown

© The IUCN Red List of Threatened Species: Delphinus delphis Gulf of Corinth subpopulation – published in 2020. 3 https://dx.doi.org/10.2305/IUCN.UK.2020-2.RLTS.T156206333A170381113.en Habitat and Ecology (see Appendix for additional information) Movements of Common Dolphins in the Gulf of Corinth tracked between 2011 and 2017 indicated a preference for deep waters in the central and southern sectors of the Gulf (Bearzi et al. 2016, Bonizzoni et al. 2019).

Common Dolphins in Greece normally prefer continental shelf waters where they target epipelagic schooling fish. In the Gulf of Corinth, their preference for deep waters is consistent with the hypothesis of Common Dolphins having modified their behaviour and habitat preferences to live in mixed-species groups with Striped Dolphins (Bonizzoni et al. 2019). Common Dolphins scattered within large Striped Dolphin groups were never observed schooling and chasing epipelagic fish at the surface (a typical behaviour of Common Dolphins in other Mediterranean areas; Bonizzoni et al. 2019). Sharing deep- water habitat with Striped Dolphins and perhaps adapting to their foraging behaviour may have come at a cost for Common Dolphins, considering that the two species have different diets and Common Dolphins have higher metabolic rates (Spitz et al. 2012).

Systems: Marine

Use and Trade (see Appendix for additional information) The Gulf of Corinth Common Dolphin subpopulation is not used for bait or consumption, and is not subject to trade.

Threats (see Appendix for additional information) The Gulf of Corinth Common Dolphin subpopulation currently is not subject to hunting, and there is no information on past killings within this geographic area. Threats to the Gulf of Corinth Common Dolphin subpopulation include prey depletion, food-web competition and habitat degradation caused by fishing (including illegal fishing), exposure to toxic pollutants via the food web, and acoustic disturbance from seismic surveys (Bearzi et al. 2016, Bonizzoni et al. 2019). While there is virtually no information on the occurrence of bycatch within the Gulf of Corinth, Common Dolphin mortality in fishing gear has been recorded in the eastern Ionian Sea areas and in other areas of Greece (Bearzi et al. 2008, Frantzis 2009). Reduced availability of important prey caused by overfishing has long been identified as one of the primary reasons behind the dramatic decline of Common Dolphins in the Mediterranean (Bearzi et al. 2003), particularly in western Greece (Bearzi et al. 2008; Piroddi et al. 2010, 2011). In the Gulf of Corinth, the food-web damage caused by excessive fishing combines with the mechanical and biological damage to the seabed caused by destructive fishing methods such as bottom trawling, as well as by illegal beach seining and purse seining in shallow coastal waters (Bearzi et al. 2016, Bonizzoni et al. 2019). These fishing methods are known to cause dramatic alterations of the substrate and to reduce the mass and diversity of benthic biological systems, with the potential to compromise the productivity, functionality and complexity of the Gulf ecosystem. Colossal amounts of hazardous industrial waste have been dumped into the Gulf for over half a century. Preferred Common Dolphin habitat overlaps with areas of massive disposal of residue from extraction of aluminium (‘red mud’, including iron oxides, aluminium and titanium). While red mud disposal at sea stopped in 2011, contamination through the food web may expose Common Dolphins to the immunotoxic and other detrimental effects of persistent environmental pollutants (Bearzi et al. 2016, Bonizzoni et al. 2019).

Other ongoing threats to Gulf of Corinth Common Dolphins include anthropogenic noise caused by

© The IUCN Red List of Threatened Species: Delphinus delphis Gulf of Corinth subpopulation – published in 2020. 4 https://dx.doi.org/10.2305/IUCN.UK.2020-2.RLTS.T156206333A170381113.en geophysical research and seismic surveys (Bearzi et al. 2016). For a discussion of general threats that may arise from other human activity in the wider region, see Bearzi et al. 2003.

Finally, the recently confirmed hybridization with 60-fold more abundant Striped Dolphins threatens the persistence of Common Dolphins in the Gulf of Corinth (Antoniou et al. 2019, Santostasi et al. 2018). It has been suggested that the steep decline of Common Dolphins caused by human activities (Bearzi et al. 2003) has led to a scarcity of potential mates, and this likely contributed to the observed breeding and admixture with Striped Dolphins (Frantzis and Herzing 2002, Antoniou et al. 2019). Projections of Common Dolphin viability that did not include the effects of hybridization estimated a 50% probability of extinction after 15 years (Santostasi et al. 2018). However, when the effects of hybridization were taken into account, Common Dolphins had a 100% probability of extinction after 16 years, regardless of the hybrid-fitness scenario (Santostasi et al. in press). While the two predictions are not entirely comparable due to different methodologies, these results suggest that hybridization poses an additional and important threat. The effects of extant anthropogenic threats were not considered, and therefore assumed to be null in the projections described above. Important ongoing threats, however, do exist and have been documented in the Gulf of Corinth (Bearzi et al. 2016, Bonizzoni et al. 2019). Additionally, hybridization and admixture with a 60-fold larger population of striped dolphins is a source of grave concern (Frantzis and Herzing 2002, Bearzi et al. 2016, Antoniou et al. 2018), as hybridization and introgression increase the probability of extinction through genetic and demographic swamping (Allendorf et al. 2001, Santostasi et al. in press).

Conservation Actions (see Appendix for additional information) The Common Dolphin subpopulation in the Mediterranean Sea is classified as Endangered in the IUCN Red List (Bearzi 2003). In the waters of Greece, including the Gulf of Corinth, a variety of binding national, regional and international legislative instruments require the protection of all cetacean species (for a review of the international legal framework for marine mammal conservation in the Mediterranean Sea see Scovazzi 2016).

The semi-enclosed Gulf of Corinth is one of 26 areas characterised as IMMAs in the Mediterranean region (IUCN 2017). Its inclusion was based on the occurrence of isolated populations of Common Dolphins and Striped Dolphins. The management actions necessary to protect cetaceans in Greece were outlined in the National Strategy and Action Plan for the conservation of cetaceans in Greece, 2010–2015 (Notarbartolo di Sciara and Bearzi 2010), which identified the Gulf of Corinth as an area of special conservation importance. Earlier on, in 2007, the Agreement on the Conservation of Cetaceans of the Black Sea, Mediterranean Sea, and Contiguous Atlantic Area (ACCOBAMS), ratified by Greece, had already listed the Gulf of Corinth as an area of special importance for Common Dolphins and other cetaceans, calling for the creation of a Marine Protected Area (resolution 3.22; ACCOBAMS 2007). In February 2018 the entire Gulf of Corinth was included in the EU Natura 2000 network (Area code GR2520007, Law 4519/2018).

Recent projections suggest that the chances of Common Dolphin recovery are scant. However, recovery would be possible if conservation measures were established and enforced. Considering the severity of the situation, immediate action should be taken to mitigate anthropogenic impacts known or suspected to have a negative impact on Common Dolphins in the Gulf of Corinth. Fisheries management measures aimed at the recovery of depleted fish stocks (particularly of Common Dolphin key prey) have been identified as a priority for Common Dolphin recovery in the Ionian Sea (Bearzi et al. 2008, Piroddi et al.

© The IUCN Red List of Threatened Species: Delphinus delphis Gulf of Corinth subpopulation – published in 2020. 5 https://dx.doi.org/10.2305/IUCN.UK.2020-2.RLTS.T156206333A170381113.en 2011). Such measures should be implemented and enforced without delay in the Gulf of Corinth, targeting as a matter of priority those commercial fisheries known to cause food-web damage and deplete Common Dolphin prey, including purse seiners and trawlers. Underwater noise (e.g. caused by seismic surveys) should be avoided. Pollutant discharges should be curtailed (also considering the large amount of industrial waste discharged into the Gulf over the last 50 years; Bearzi et al. 2016).

The repeatedly advocated creation of a marine protected area in the Gulf of Corinth (ACCOBAMS 2007, resolution 3.22; Notarbartolo di Sciara and Bearzi 2010) could contribute to the recovery and long-term survival of Common Dolphins, as long as protection includes a total ban of purse seining, beach seining and trawling and a strict enforcement (Bonizzoni et al. 2019).

The killing and harming of Common Dolphins (and all other marine mammals) in Greece is illegal. However, no specific conservation action was put in place specifically to protect Common Dolphins, or mitigate threats to the subpopulation living in the Gulf of Corinth.

No additional Research is needed before relevant conservation action is taken in the Gulf of Corinth. Low Common Dolphin numbers and negative trends in abundance imply a high immediate risk of geographic eradication. The killing and harming of Common Dolphins (and all other marine mammals) in Greece is illegal. However, no specific conservation action was put in place specifically to protect Common Dolphins, or mitigate threats to the subpopulation living in the Gulf of Corinth. Credits

Assessor(s): Bearzi, G., Bonizzoni, S. & Santostasi, N.

Reviewer(s): Reeves, R. & Taylor, B.L.

Contributor(s): Braulik, G.

Authority/Authorities: IUCN SSC Cetacean Specialist Group (dolphins, porpoises and whales)

© The IUCN Red List of Threatened Species: Delphinus delphis Gulf of Corinth subpopulation – published in 2020. 6 https://dx.doi.org/10.2305/IUCN.UK.2020-2.RLTS.T156206333A170381113.en Bibliography ACCOBAMS. 2007. Report of the 3rd meeting of the contracting parties to ACCOBAMS, the UNEP/CMS Agreement on the Conservation of Cetaceans in the Black Sea, Mediterranean Sea and contiguous Atlantic Area. Dubrovnik, Croatia, 22-25 October.

Allendorf FW, Leary RF, Spruell P, Wenburg JK. 2001. The problems with hybrids: setting conservation guidelines. Trends in Ecology & Evolution 16: 613-622.

Antoniou, A., Frantzis, A., Alexiadou, P., Paschou, N., and Poulakakis, N. 2018. Evidence of introgressive hybridization between Stenella coeruleoalba and Delphinus delphis in the Greek Seas. Molecular Phylogenetics and Evolution 129: 325-337.

Bearzi, G. 2003. Delphinus delphis (Mediterranean subpopulation). The IUCN Red List of Threatened Species 2003: e.T41762A10557372. https://dx.doi.org/10.2305/IUCN.UK.2003.RLTS.T41762A10557372.en. Downloaded on 14 April 2020.

Bearzi, G., Agazzi, S., Gonzalvo, J., Costa, M., Bonizzoni, S., Politi, E., Piroddi, C. & Reeves. R.R. 2008. Overfishing and the disappearance of short-beaked common dolphins from western Greece. Endangered Species Research 5(1-12).

Bearzi, G., Bonizzoni, S., Agazzi, S., Gonzalvo, J., and Currey, R.J.C. 2011. Striped dolphins and short- beaked common dolphins in the Gulf of Corinth, Greece: Abundance estimates from dorsal fin photographs. Marine Mammal Science 27: E165-E184.

Bearzi, G., Bonizzoni, S. and Gonzalvo, J. 2011. Dolphins and coastal fisheries within a marine protected area: mismatch between dolphin occurrence and reported depredation. Aquatic Conservation: Marine and Freshwater Ecosystems 21(3): 261-267.

Bearzi, G., Bonizzoni, S., Santostasi, N.L., Furey, N.B., Eddy, L., Valavanis, V.D., and Gimenez, O. 2016. Dolphins in a scaled-down Mediterranean: The Gulf of Corinth’s odontocetes. In: G. Notarbartolo di Sciara, M. Podestà, and B.E. Curry (eds), Advances in Marine Biology, pp. 297-331. Academic Press, Oxford.

Bearzi, G., Notarbartolo di Sciara, G., Reeves, R.R., Cañadas, A., and Frantzis, A. 2004. Conservation Plan for short-beaked common dolphins in the Mediterranean Sea. ACCOBAMS, Agreement on the Conservation of Cetaceans of the Black Sea, Mediterranean Sea and Contiguous Atlantic Area.

Bearzi, G., Politi, E., Agazzi, S. and Azzellino, A. 2006. Prey depletion caused by overfishing and the decline of marine megafauna in eastern Ionian Sea coastal waters (central Mediterranean). Biological Conservation 127(4): 373-382.

Bearzi, G, Reeves, R.R., Notarbartolo di Sciara, G., Politi, E., Canadas, A., Frantzis, A., and Mussi, B. 2003. Ecology, status and conservation of short-beaked Common Dolphins Delphinus delphis in the Mediterranean Sea. Mammal Review 33: 224-252.

Bonizzoni, S., Furey, N.B., Santostasi, N.L., Eddy, L., Valavanis, V.D. and Bearzi, G. 2019. Modelling dolphin distribution within an Important Marine Mammal Area in Greece to support spatial management planning. Aquatic Conservation: Marine and Freshwater Ecosystems: doi.org/10.1002/aqc.3148.

Frantzis, A. 2009. Cetaceans in Greece: present status of kowledge. Initiative for the Conservation of Cetaceans in Greece, Athens, Greece.

Frantzis, A., Alexiadrou, P., Paximadis, G., Politi, E., Gannier, A. and Corsini-Foka, M. 2003. Current knowledge of the cetacean fauna of the Greek seas. Journal of Cetacean Research and Management 5(3): 219-232.

© The IUCN Red List of Threatened Species: Delphinus delphis Gulf of Corinth subpopulation – published in 2020. 7 https://dx.doi.org/10.2305/IUCN.UK.2020-2.RLTS.T156206333A170381113.en Frantzis, A. and Herzing, D.L. 2002. Mixed species associations of Striped Dolphin (Stenella coeruleoalba), Short-beaked Common Dolphin (Delphinus delphis) and Risso's Dolphin (Grampus griseus), in the Gulf of Corinth (Greece, Mediterranean Sea). Aquatic Mammals 28(2): 188-197.

Gärdenfors, U., Hilton-Taylor, C., Mace, G.M., and Rodríguez, J.P. 2001. The application of IUCN Red List criteria at regional levels. Conservation Biology 15: 1206-1212.

Gkafas, A., Podiadis, V., Tsigenopoulos, K., Reid, B., Karpouzli, E., Verriopoulos, G., Mamuris, Z., Magoulas, A., and Exadactylos, A. 2007. Genetic polymorphism and population structure of the striped dolphin, Stenella coeruleoalba, and the common dolphin, Delphinus delphis, within the ACCOBAMS area. Proceedings 10th International Conference on Environmental Science and Technology, Kos Island, Greece, 5–7 September 2007: 426–431.

Gkafas, G. A. 2011. Molecular ecology and fitness of striped dolphins (Stenella coeruleoalba, Meyen, 1833) and common (Delphinus delphis, Linnaeus, 1758) dolphins. PhD Thesis, Durham University. http://etheses.dur.ac.uk/743/.

Hammond, P. S., Bearzi, G., Bjørge, A., Forney, K., Karczmarski, L., Kasuya, T., Perrin, W. F., Scott, M. D., Wang, J. Y., Wells, R. S., and Wilson, B. 2008. Delphinus capensis. In 'The IUCN Red List of Threatened Species'. Version 2013.1. Available at: www.iucnredlist.org. (Accessed: 16 June 2013).

Hammond, P.S., Bearzi, G., Bjørge, A., Forney, K., Karczmarski, L., Kasuya, T., Perrin, W.F., Scott, M.D., Wang, J.Y., Wells, R.S. and Wilson, B. 2008. Delphinus delphis. The IUCN Red List of Threatened Species 2008: e.T6336A12649851. https://dx.doi.org/10.2305/IUCN.UK.2008.RLTS.T6336A12649851.en. Downloaded on 14 April 2020.

IUCN. 2020. The IUCN Red List of Threatened Species. Version 2020-2. Available at: www.iucnredlist.org. (Accessed: 13 June 2020).

IUCN Marine Mammal Protected Area Task Force. 2017. Final Report of the Workshop: First IMMA Regional Workshop for the Mediterranean, Chania, Greece, 24–28 October 2016. Marine Mammal Protected Area Task Force of the International Union for Conservation of Nature, Gland. http://www.marinemammalhabitat.org/download/report-regional-workshop-mediterranean-important- marine-mammal-areas/.

Levin, D. A. 2002. Hybridization and extinction. American Scientist 90: 254-261.

Moura, A. E. 2010. Investigating the relative influence of genetic drift and natural selection in shaping patterns of population structure in Delphinids (Delphinus delphis: Tursiops spp.). PhD thesis. Durham University. http://etheses.dur.ac.uk/755/.

Moura, A.E., Natoli, A., Rogan, E., and Hoelzel, A.R. 2013. Atypical panmixia in a European dolphin species (Delphinus delphis): Implications for the evolution of diversity across oceanic boundaries. Journal of Evolutionary Biology 26: 63-75.

Natoli, A., Cañadas, A., Vaquero, C., Politi, E., Fernandez-Navarro, P. and Hoelzel, A.R. 2008. Conservation genetics of the short-beaked common dolphin (Delphinus delphis) in the Mediterranean Sea and in the eastern North Atlantic Ocean. Conservation Genetics: s10592-007-9481-1.

Notarbartolo di Sciara, G., and Bearzi, G. 2010. National strategy and action plan for the conservation of cetaceans in Greece, 2010-2015. Initiative for the Conservation of Cetaceans in Greece , Athens, Greece.

Piroddi, C., Bearzi, G., and Christensen, V. 2010. Effects of local fisheries and ocean productivity on the northeastern Ionian Sea ecosystem. Biological Conservation 144: 2490-2498.

Piroddi, C., Bearzi, G., Gonzalvo Villegas, J., and Christensen, V. 2011. From common to rare: The case of

© The IUCN Red List of Threatened Species: Delphinus delphis Gulf of Corinth subpopulation – published in 2020. 8 https://dx.doi.org/10.2305/IUCN.UK.2020-2.RLTS.T156206333A170381113.en the Mediterranean common dolphin. Biological Conservation 144: 2490-2498.

Santostasi, N.L., Bonizzoni, S., Bearzi, G., Eddy, L., and Gimenez, O. 2016. A robust design capture- recapture analysis of abundance, survival and temporary emigration of three odontocete species in the Gulf of Corinth, Greece. PLoS ONE 11: e0166650.

Santostasi, N.L., Bonizzoni, S., Gimenez, O., Eddy, L., and Bearzi, G. 2018. Common dolphins in the Gulf of Corinth are Critically Endangered. Aquatic Conservation: Marine and Freshwater Ecosystems: DOI: 10.1002/aqc.2963.

Santostasi, N.L., Ciucci, P., Bearzi, G., Bonizzoni, S., and Gimenez, O. in press. Assessing the dynamics of hybridization through a matrix modelling approach. Ecological Modelling.

Scovazzi, T. 2016. The international legal framework for marine mammal conservation in the Mediterranean Sea. In: G. Notarbartolo di Sciara, M. Podestà, and B. E. Curry (eds), Advances in Marine Biology, pp. 387–416. Academic Press, Oxford.

Spitz, J., Trites, A.W., Becquet, V., Brind’Amour, A., Cherel, Y., Galois, R., and Ridoux, V. 2012. Cost of living dictates what whales, dolphins and porpoises eat: The importance of prey quality on predator foraging strategies. PLoS ONE 7: e50096.

Taylor, B.L. 2005. Identifying units to conserve. In: J.E. Reynolds, III, W.F. Perrin, R.R. Reeves, S. Montgomery, and T.J. Ragen (eds), Marine mammal research: Conservation beyond crisis, pp. 142-162. John Hopkins University Press, Baltimore, MA.

Taylor, B.L., Chivers, S.J., Larese, J. and Perrin, W.F. 2007. Generation length and percent mature estimates for IUCN assessments of Cetaceans. NOAA Southwest Fisheries Science Center, La Jolla, California. Administrative Report LJ-07-01.

Citation Bearzi, G., Bonizzoni, S. & Santostasi, N. 2020. Delphinus delphis(Gulf of Corinth subpopulation). The IUCN Red List of Threatened Species 2020: e.T156206333A170381113. https://dx.doi.org/10.2305/IUCN.UK.2020-2.RLTS.T156206333A170381113.en

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External Resources For Supplementary Material, and for Images and External Links to Additional Information, please see the Red List website.

Habitats (http://www.iucnredlist.org/technical-documents/classification-schemes)

Major Season Suitability Habitat Importance? 9. Marine Neritic -> 9.1. Marine Neritic - Pelagic Resident Suitable Yes

Threats (http://www.iucnredlist.org/technical-documents/classification-schemes)

Threat Timing Scope Severity Impact Score 5. Biological resource use -> 5.4. Fishing & harvesting Ongoing Whole (>90%) Slow, significant Medium aquatic resources -> 5.4.3. Unintentional effects: declines impact: 7 (subsistence/small scale) [harvest]

5. Biological resource use -> 5.4. Fishing & harvesting Ongoing Whole (>90%) Rapid declines High impact: 8 aquatic resources -> 5.4.4. Unintentional effects: (large scale) [harvest] Stresses: 2. Species Stresses -> 2.1. Species mortality 9. Pollution -> 9.1. Domestic & urban waste water -> Ongoing Minority (50%) Unknown Unknown 9.1.2. Run-off

9. Pollution -> 9.2. Industrial & military effluents -> Ongoing Majority (50- Unknown Unknown 9.2.2. Seepage from mining 90%)

9. Pollution -> 9.2. Industrial & military effluents -> Ongoing Minority (50%) Unknown Unknown 9.2.3. Type Unknown/Unrecorded

9. Pollution -> 9.3. Agricultural & forestry effluents -> Ongoing Majority (50- Unknown Unknown 9.3.3. Herbicides and pesticides 90%)

9. Pollution -> 9.6. Excess energy -> 9.6.3. Noise Ongoing Majority (50- Unknown Unknown pollution 90%)

Conservation Actions in Place (http://www.iucnredlist.org/technical-documents/classification-schemes)

Conservation Action in Place In-place education

Included in international legislation: Yes

Subject to any international management / trade controls: Yes

Conservation Actions Needed (http://www.iucnredlist.org/technical-documents/classification-schemes)

© The IUCN Red List of Threatened Species: Delphinus delphis Gulf of Corinth subpopulation – published in 2020. 10 https://dx.doi.org/10.2305/IUCN.UK.2020-2.RLTS.T156206333A170381113.en Conservation Action Needed 1. Land/water protection -> 1.1. Site/area protection

1. Land/water protection -> 1.2. Resource & habitat protection

2. Land/water management -> 2.1. Site/area management

2. Land/water management -> 2.3. Habitat & natural process restoration

4. Education & awareness -> 4.3. Awareness & communications

5. Law & policy -> 5.1. Legislation -> 5.1.1. International level

5. Law & policy -> 5.1. Legislation -> 5.1.2. National level

5. Law & policy -> 5.2. Policies and regulations

5. Law & policy -> 5.3. Private sector standards & codes

5. Law & policy -> 5.4. Compliance and enforcement -> 5.4.1. International level

5. Law & policy -> 5.4. Compliance and enforcement -> 5.4.2. National level

6. Livelihood, economic & other incentives -> 6.1. Linked enterprises & livelihood alternatives

6. Livelihood, economic & other incentives -> 6.2. Substitution

Additional Data Fields

Population Number of mature individuals: 10

Continuing decline of mature individuals: Unknown

Extreme fluctuations: Unknown

Habitats and Ecology Continuing decline in area, extent and/or quality of habitat: Unknown

Generation Length (years): 14.8

Movement patterns: Not a Migrant

© The IUCN Red List of Threatened Species: Delphinus delphis Gulf of Corinth subpopulation – published in 2020. 11 https://dx.doi.org/10.2305/IUCN.UK.2020-2.RLTS.T156206333A170381113.en The IUCN Red List of Threatened Species™ ISSN 2307-8235 (online) IUCN 2020: T156206333A170381113 Scope(s): Global Language: English

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The IUCN Red List of Threatened Species™ is produced and managed by the IUCN Global Species Programme, the IUCN Species Survival Commission (SSC) and The IUCN Red List Partnership.

The IUCN Red List Partners are: Arizona State University; BirdLife International; Botanic Gardens Conservation International; Conservation International; NatureServe; Royal Botanic Gardens, Kew; Sapienza University of Rome; Texas A&M University; and Zoological Society of London.

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