Fisheries Management and Ecology Fisheries Management and Ecology, 2014, 21, 122–132 IUCN Red List of freshwater fishes and lampreys in Flanders (north Belgium) H. VERREYCKEN, C. BELPAIRE, G. VAN THUYNE & J. BREINE Research Institute for Nature and Forest (INBO), Groenendaal (Hoeilaart), Belgium D. BUYSSE, J. COECK, A. MOUTON, M. STEVENS & T. VAN DEN NEUCKER Research Institute for Nature and Forest (INBO), Brussels, Belgium L. DE BRUYN Research Institute for Nature and Forest (INBO), Brussels, Belgium Evolutionary Ecology Group, Department of Biology, University of Antwerp, Antwerp, Belgium D. MAES Research Institute for Nature and Forest (INBO), Brussels, Belgium Abstract Red Lists are used to assess the extinction risk of species. Regional IUCN criteria were applied to categorise 42 indigenous freshwater fish species in Flanders into Red List categories. As such, three species are assessed as Regionally Extinct, eight as Critically Endangered, two as Endangered and eight as Vulnerable. A further five species are considered Near Threatened, 15 species as Least Concern and one species is Data Deficient. Five species disappeared from the Regionally Extinct category compared with the previous Red List (1988) as a consequence of improved water quality of estuaries and reintroduction programmes. In total, 62% of the freshwater fish species in Flanders was considered extinct or threatened. This is higher than neighbouring regions and Europe as a whole (44%). This new Red List of freshwater fishes in Flanders can be used to inform conservation actions. KEYWORDS: conservation, distribution, freshwater fish, regional IUCN criteria, threatened species. Council in 2000 (IUCN 2001). In 2003, these criteria Introduction were adapted to the regional (non-global) level (IUCN Red Lists are used to assess the extinction risk of species 2003). Recently, Maes et al. (2012) used these regional based on quantitative criteria developed by the Interna- IUCN criteria in Flanders, the most northern of the three tional Union for Conservation of Nature (IUCN). In the administrative regions of Belgium, and tested how they past, Red Lists were usually compiled using expert could be applied in this small geographical region judgement and/or qualitative criteria (Mace & Lande (13 500 km2) using butterflies as a test case. 1991; Mace & Collar 1995). In 1991, the IUCN agreed Although initially not developed for fish (Kottelat & upon the use of quantitative criteria for the classification Freyhof 2007), the IUCN criteria definitely allow cate- of species in threat categories on a global level (Mace & gorisation of fish species according to their extinction Lande 1991). These criteria were, however, repeatedly risks. Some authors (e.g. Keith & Marion 2002), how- revised before eventually being adopted by the IUCN ever, have chosen to make adaptations to the criteria to Correspondence: Hugo Verreycken, Research Institute for Nature and Forest (INBO), Duboislaan 14, B-1560 Groenendaal (Hoeilaart), Belgium (e-mail: [email protected]) 122 doi: 10.1111/fme.12052 © 2013 John Wiley & Sons Ltd THREAT STATUS OF FISHES IN BELGIUM 123 allocate a fish species to an IUCN category more accu- non-native species such as carp, Cyprinus carpio L., and rately. Many European countries and regions (such as pikeperch, Sander lucioperca (L.), were excluded. In this Great Britain, Scotland, Ireland, France, Spain, Slovenia way, 42 indigenous freshwater fish and lamprey species and the Netherlands) have drawn up Red Lists of fresh- (hereafter referred to as fish species) were retained for an water fishes. At a larger scale, the extinction risk of 531 assessment of their Red List status. European freshwater fishes was recently assessed in the Scientific and vernacular names largely follow first European Red List (Freyhof & Brooks 2011). This Wheeler (1992) and, additionally, FishBase (Froese & review concluded that overall, at least 40% of Europe’s Pauly 2013). Recently, the European Cottus genus has freshwater fishes are threatened or extinct on a continen- been revised, and Cottus gobio L. was split up into sev- tal scale. A further 4% of freshwater fishes are consid- eral new species (Freyhof et al. 2005) of which only ered Near Threatened. This is one of the highest threat bullhead, C. perifretum, Freyhof, Kottelat and Nolte, and levels of any major taxonomic group assessed to date for Rhine sculpin, C. rhenanus, Freyhof, Kottelat and Nolte Europe (Freyhof & Brooks 2011). are native to Flanders. However, because of the diffi- In Flanders, the first Red List of freshwater fishes was culty to identify these species in the field, all data published in Dutch in 1998 (Vandelannoote & Coeck recorded under these three species names (C. gobio, 1998) using the Red List categories as defined by Maes C. perifretum and C. rhenanus) were combined in this et al. (1995). Because of improved water and habitat analysis and are referred to here as bullhead, C. gobio. quality and reintroductions, fish communities have For the Red List assessment, two separate data files changed recently, which in turn has necessitated revising were compiled: (1) a trend data set that was used to cal- the Red List. Moreover, a large data set on freshwater culate temporal trends in abundance and occurrence; and fish distribution and abundance over the last two decades (2) a distribution data set to calculate an area of occu- has recently become available, forming the base for a pancy (AOO = the sum of the area of the river sub- Red List update. This study presents the new Red List basins in which a species was found). The trend data for freshwater fishes in Flanders using the latest IUCN were obtained from standardised fish stock surveys using criteria and documents how IUCN criteria such as electric fishing and fyke netting performed by the geographical range and population trend can be derived Research Institute for Nature and Forest (INBO 2013). from monitoring and distribution data. The number of individuals caught was transformed into catch-per-unit-effort (CPUE, i.e. the number of individu- als 100 mÀ1 electric fishing or the number of individuals Methods À À fyke 1 day 1). More detailed descriptions of sampling protocol and technical equipment are available in Belp- Study area and data aire et al. (2000). As the standardised fishing has only Data on freshwater fish distribution and abundance were been applied rigorously since 1996, all data prior to that collected between 1996 and 2011 during fish stock year were excluded from the analysis. Due to low num- assessments at 3585 sampling sites in Flanders (approxi- bers, winter catch data (December, January and Febru- mately 14 sites kmÀ2 water surface area). These sites ary) were also excluded from the analysis. The trend can be characterised as riverine habitats, including head data set consisted of 28 479 records (i.e. species, loca- streams, tributaries and canals and are part of the drain- tion, year, CPUE). The distribution data, on the other age basins of the rivers Yser, Scheldt and Meuse hand, consisted of readily available fish data in Flanders (Fig. 1). These three drainage basins are divided into 11 since 1996 and were compiled from diverse sources: (1) Flemish river catchments, which again are divided into the trend data (INBO 2013; see above); (2) all local dis- 102 sub-basins. tribution data from research projects [including projects In accordance with the European Red List of Freshwater under the authority of the Flemish Agency for Nature Fishes (Freyhof & Brooks 2011), all species of freshwater and Forest (ANB)]; and (3) validated data from volun- fishes and lampreys recorded from lotic fresh waters in teers (checked by experts) (Natuurpunt 2013). The total Flanders were included. However, marine migrants and number of records [species, year, site (expressed as species of brackish waters were also included if they regu- UTM 1 9 1-km² grid cell)] for this distribution data set larly enter freshwater habitats. Species were only included consisted of 28 563 records. if the record was based on reliably identified individuals documented with adequate catch data (locality and date of IUCN criteria catch). The conservative approach was used to define indigenous species and thus all non-native species listed The IUCN distinguishes nine categories for listing spe- in Verreycken et al. (2007), including long-established cies, with two additional categories in national and © 2013 John Wiley & Sons Ltd 124 H. VERREYCKEN ET AL. Figure 1. Map of Flanders with locations sampled in the period 1996–2011; the locations in black were surveyed at least twice during the period 1996–2011 and were used to calculate temporal changes in population and distribution. Grey dots indicate locations surveyed only once in the period 1996–2011 and were used to calculate the geographic range. regional Red Lists (IUCN Standards & Petitions Work- population reduction during the last 10 years; (B) small ing Group 2010). Three categories refer to extinct spe- geographical range; (C) small population size and cies: Extinct (EX – globally extinct species), Extinct in decline; (D) very small or restricted population; and (E) the Wild (EXW – species for which populations are only quantitative analysis of extinction risk (Mace et al. present in captivity) and Regionally Extinct (RE – spe- 2008). cies that are extinct in the focal region). Five categories specify the differences in extinction risk: Critically Applying IUCN criteria to Flanders Endangered (CR), Endangered (EN), Vulnerable (VU), Near Threatened (NT) and Least Concern (LC). The Only IUCN criteria A and B could be used for the Red three remaining categories are Data Deficient (DD – spe- List classification of fishes in Flanders. Data to use the cies for which insufficient data are available to classify other criteria (C, D and E: absolute population numbers) them in one of the Red List categories), Not Applicable were not available. These data are difficult to obtain for (NA – species for which the Red List criteria do not fish species.