Little is known about the marine life-history phase of the anadromous sea lamprey Petromyzon marinus. The most widely accepted hypothesis suggests a hematophagous feeding phase of 2.5 yr. We captured and tagged (individually numbered T-bar anchor tags) 408 postmetamorphic sea lampreys during the onset of the hematophagous feeding phase in the River Ulla and its estuary (NW Spain). One marked sea lamprey was recaptured during its spawning migration (total length: 895 mm, weight: 1218 g). This individual had been marked 13.5 mo before recapture, and had measured 218 mm and 20 g. Our results suggest that at least a portion of the sea lamprey population can reach adult size in 1 yr of hematophagous feeding. This further suggests a period between completion of metamorphosis and reproduction of 1.5 yr (18 to 20 mo).

Although the sea lamprey, Petromyzon marinus Linnaeus, 1758, is a threatened species in Europe, available data on the condition and dynamics of its populations are very limited. Thus, electrofishing surveys were conducted annually between 2007 and 2011, so as to study the status and trends of larval populations of P. marinus in north-western Spain. In addition, data from other European regions were compiled. The density and biomass (mean AE standard error) of ammocoetes in selected areas of larval habitat in north-western Spain were 11.0 AE 1.44 individuals m À2 and 15.1 AE 2.64 g m À2 , and showed signs of a population increase during the study period. However, conservation status of P. marinus was not considered favourable because of several factors, such as the widespread presence of obstacles (restriction of migration and habitat availability), along with some cases of organic pollution. Results and available data suggest that the largest populations of P. marinus as well as the main fisheries are located throughout the south-western areas of Europe (north-central Portugal, north-north-west of Spain and west-south-west of France). Signs of population increases were also registered in other European regions; however, more data are needed to confirm whether this trend has any relevance to a possible overall recovery.

1. Fisheries and the presence of low-head obstacles are considered major threats for anadromous lampreys, including the sea lamprey (Petromyzon marinus). Nonetheless, research is still needed to increase our understanding of their effect and to implement effective conservation and management measures. Petromyzon marinus

Single pass electrofishing method for assessment and monitoring of larval lamprey populationsOur work aims at calibrating and standardizing the single pass protocol of electrofishing to assess and monitor larval lamprey populations, mainly for European populations of sea lamprey (Petromyzon marinus). The method is considered cost-effective and appropriate for use both on the scale of management decisions (from river or watershed to a regional or national scale) and as a routine assessment tool as required by the European Union Habitats Directive. Additionally, the larval surveys may be reconciled with routine electrofishing surveys for fish species, to further reduce costs. In our case, the escapement of larvae from the sampling area when using electrofishing corresponded to 18 % of larvae and 17 % of larval biomass. The general effectiveness of the protocol to determine the density and biomass of age-1 and older larvae in the prospected area was 68 % and 70 %, respectively. Finally, reference categories for density and biomass of larval populations of P. marinus in NW of the Iberian Peninsula are provided.

No abstract

Cyanobacterial blooms constitute a global environmental concern, with sometimes serious implications for human and animal health. Consequently, they represent a major problem in the management of water and aquatic ecosystems. The design of good quality control and management programs is therefore imperative and, for this, a good understanding of the state of the art becomes essential. In Spain, information related to freshwater cyanobacteria is somewhat scattered. Thus, the main objective of this work is to gather all the available information related to cyanobacteria in Spanish artificial water bodies (reservoirs), with special attention to episodes of massive proliferation and probable toxic events. Data for this review were obtained from scientific papers, technical reports, and from the websites of the different Spanish basin organizations. From the review carried out, it is relevant that: cyanobacteria species have been recorded in 252 of the 988 existing reservoirs and blooms in 91 of them (most of them destined for water supply), potentially toxic cyanobacteria are widespread, and that occurrence of blooms has increased recently. The latter could be attributed to a spread monitoring effort. Nevertheless, the effect of the increasing eutrophication and climate change should not be underestimated. In addition to the data compilation, the relation between the cyanobacteria recorded in the Spanish water reservoirs and the geological area where the reservoirs are located has been analyzed.

This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

An update on the distribution of Cobitis paludica in the NW Iberian PeninsulaIt has long been believed that the southern Iberian spined-loach (Cobitis paludica) was introduced to the northwest of the Iberian Peninsula. This paper updates the distribution of the southern Iberian spined-loach in the NW Iberian Peninsula with six new localities in the rivers Furnia, Hospital, Pego, Pontiñas, Tripes and Ulla, some of which with substantial populations (Pego and Tripes). This study supports the view that the southern Iberian spined-loach is native in the NW Iberian Peninsula, where its populations are mostly small and appear to be very fragmented. It is therefore critical that sampling effort is increased, to improve our knowledge of the species' abundance, distribution and population dynamics.