Out of Sight, Out of Mind: How Conservation Is Failing European Porpoises

Abstract

The conservation of harbor porpoises (Phocoena phocoena) appears to be failing in Europe. There are particular concerns about this species in the Baltic Proper, Black, and Mediterranean Seas, as well as in the Northeast Atlantic, including the Iberian population, off the Spanish and Portuguese coasts. The Baltic Proper porpoise is “critically endangered,” with a population only in the low hundreds, and the Scientific Committee of the International Whaling Commission has repeatedly called for action to ensure its survival. In 2020, the Committee issued a series of recommendations relating to it and the Iberian population. Similarly, the Black Sea harbor porpoise, Phocoena phocoena ssp. relicta, is classified by the IUCN as endangered. Another population which may be genetically distinct is the West Greenland harbor porpoise, which is hunted without quotas or close seasons. European cetaceans and their habitats are covered by a number of international and regional conventions and agreements and, under European Union law, are “highly protected.” In practice, however, these legal protections have failed to generate effective conservation. For example, Special Areas of Conservation (SACs) are required for them and, although sites have been designated in some marine areas/countries, in the absence of appropriate management plans, SACs cannot be expected to help improve the harbor porpoise's conservation status. Compared to many other species, porpoises are relatively long-lived with low reproductive capacity and only poor public recognition. Conservation and management efforts are caught up in a complicated nexus of interactions involving a web of commitments under international conventions and agreements, European environmental laws, and European fisheries policy. However, public disinterest, lack of political will to implement conservation measures, and complicated fishing-related issues hinder any real progress. More positively, recent advice from the International Council for the Exploration of the Seas (ICES) provides a new scientific foundation for conservation action to address fisheries bycatch in the Baltic Proper harbor porpoise population. Populations of other porpoise species (family Phocoenidae) are also threatened, most notably the global population of the critically endangered vaquita, or Gulf of California porpoise (Phocoena sinus). The common threats and factors affecting porpoise populations are discussed and recommendations offered.

Harbor porpoise losing its edges: genetic time series suggests a rapid population decline in Iberian waters over the last 30 years

“…This species is thus expected to be particularly sensitive to climate changes (Heide-Jørgensen et al, 2011). Besides, due their coastal distribution, thousands of harbor porpoises are also killed accidentally by commercial fisheries threatening local populations to a level that is still hard to quantify, but which is likely unsustainable especially with a highly fluctuating environment (Carlén et al, 2021;IMR-NAMMCO, 2019;Vingada & Eira, 2018).…”

Evolutionary history and seascape genomics of Harbour porpoises (Phocoena phocoena) across environmental gradients in the North Atlantic and adjacent waters

“…In this study, we have analyzed whole-genome sequencing data of a critically endangered population, the Proper Baltic Sea harbour porpoise, and an endangered subspecies, the Black Sea harbour porpoise. Our results provide genomic evidence that the Proper Baltic Sea population is a distinct lineage (Figure 2, S4) and, given the poor status of the population, urgent measures to protect the species must be implemented (Carlen, Nunny & Simmonds, 2021). Previous studies have shown that microsatellite data does not yield enough statistical power to identify the fine population structure of the harbour porpoise in Baltic waters (Wiemann et al, 2010;Lah et al, 2016).…”

Best Practices for Assessing and Managing Bycatch of Marine Mammals

“…Although we have highlighted the important issue of building capacity for conducting assessments of marine mammal bycatch throughout the world, even areas with considerable capacity have not necessarily achieved meaningful bycatch reduction. For example, several authors recently argue that the European Union (EU) has failed to adequately assess and mitigate bycatch of small cetaceans (Bearzi and Reeves, 2021;Carlén et al, 2021;Dolman et al, 2021;Rogan et al, 2021); they suggest this is due to diffuse management authority, a lack of political will, and the fact that the EU has no overarching quantitative conservation objectives. Rogan et al (2021) suggest the EU establish a comprehensive plan that would include quantitative management objectives, generate estimates of abundance and bycatch mortality, and establish biological reference points to guide management actions; such a plan would incorporate much of the scheme we suggest here (Figure 1) and would be consistent with best practice guidelines for reference point-based management (Curtis et al, 2015).…”