There is growing evidence to suggest that there is an increase in species extinction occurring globally. In this article, we briefly review the literature on the economics of species extinction, examining what is meant by extinction before explaining how economics has conceptualised this. The initial economics literature on species extinction focuses largely on renewable resources, in particular fisheries, but has subsequently evolved to cover many aspects of biodiversity across all physical scales, employing an increasing array of methodological tools. We also consider aspects of cultural and societal extinctions (e.g. local languages, local knowledge) and how this is positively correlated with loss of biodiversity, as well as an economist’s outlook on the potential to re-capture value post-extinction.

Southern Black Korhaan is “Vulnerable” to extinction and a South African endemic that is restricted to the area of the Northern Cape Province that is west of the Great Escarpment, and to the area south of the Great Escarpment in the Western Cape, and the western section of the Eastern Cape Province. The 1990, 2014, and 2020 land use land cover (LULC) databases prepared for South Africa were used to determine the LULC categories that best describe suitable habitat for the birds using beta regressions and data on the exact locality of the birds from BirdLasser. The South African Bird Atlas Project (SABAP) reporting rates were used to determine the change in the relative abundance of the birds between the first and second SABAP. Beta regression models were compiled using the bird’s reporting rate and the total surface area, and three other landscape metrics, of the per pentad LULC categories considered to be suitable habitat for them. These models and the SABAP reporting rates revealed that Southern Black Korhaan is adversely affected by the loss of, especially, its fynbos habitat to crop agriculture. In 2020, the area of suitable habitat available to the bird was estimated to be 2,035,526 ha on terrain with a slope of ≤4°. Southern Black Korhaan remains “Vulnerable” to extinction because of the continued decline of >30% in the size of its population over three generations (31 years). The cumulative effects of habitat fragmentation and loss on Southern Black Korhaan and other threatened taxa must be mitigated by conserving and, where appropriate, rehabilitating suitable habitat (e.g. Gouritz Cluster Biosphere Reserve’s Corridors and Rehabilitation Project) in the protected areas, critical biodiversity areas, and ecosystem support areas identified in the provincial spatial conservation plans. Together these areas form a perforated landscape that ensures maximum connectivity between the remaining patches of indigenous habitat.

In the present contribution we report, for the first time, records of the nudibranch Zelentia ninel from Norway. The species is previously known only from the Barents Sea coast in northern Russia where it was described for the first time in 2017. Records of Z. ninel from six different localities in northern Norway from 2019–2023 are presented and discussed. The identity of the specimens was determined by investigation of external and internal morphology as well as molecular analysis of preserved specimens. Photographs of live specimens and radulae of preserved specimens are presented, and species delimitation is confirmed by molecular phylogenetic analysis. In order to assess the biogeographic distribution of Z. ninel based on all available information, recent unanticipated genetic data supporting a putative occurrence of Z. ninel at the Aleutian Islands, Alaska is also discussed where we provide arguments in support of occasional anthropogenic transportation outside its natural range. The present records significantly expand the known natural range of distribution for Z. ninel and demonstrate that the species is not restricted to the Russian Barents Sea coast but that the range encompasses also at least northern Norway. These data can provide important insights to the understanding of natural ranges of marine invertebrates across biogeographical regions affected by rapid ongoing climatic change.

Biodiversity laws around the world differ, but, at their core, these laws promote the fundamental objective of preventing environmental decline and species extinctions. A variety of legal mechanisms have been implemented in domestic laws around the world to achieve this objective, including protection for habitat, environmental impact assessments and threatened species recovery plans. In many jurisdictions, if these mechanisms fail to protect a species, it may be legally declared extinct, or added to a formal list of those that have been lost. This article examines the conservation purpose and legal implications for laws about extinction. A legal power to recognise a species as extinct has the potential to foster ambition, transparency and rigorous measurement of progress against conservation goals. However, in practice, efforts to prevent extinction are applied selectively. Without an obligation to learn from extinctions, recognition of species extinctions in law may have perverse effects, or no effect at all. This article proposes a conceptual model for the role of law in relation to extinctions, highlighting opportunities to improve legal frameworks to achieve more productive and positive conservation outcomes, even as climate change and other pressures drive many more species towards extinction.

Serranus hepatus is a bycatch species in the Mediterranean trawl fishery for which knowledge on biological features such as otolith morphology is generally poor in the Mediterranean Sea. In the present study, the weight–length relationship, age, growth and ten otolith morphometric variables of this species were investigated in two distant areas, the Eastern Ionian and southwestern Aegean Seas. Isometric growth in weight was defined in both areas. Growth parameters also did not differ between the two study areas. Six of the otolith variables (radius, otolith length, otolith width, otolith area, perimeter and ellipticity) showed a significant relationship with size without significant differences between the two areas. Significant differences between the two areas were only defined for five of the morphometric variables (otolith length, width and area being the most important). Further studies to discriminate between potential stocks of S. hepatus seem to be necessary, information that is needed for stock identification, stock assessment and fisheries management.