Joana Vasconcelos

Universidad de Las Palmas de Gran Canaria | ULPGC · Department of Biology

Several artisanal fisheries target deep species. These stocks are highly sensitive to overfishing because of their slow growth and late maturation. This vulnerability is higher if species concentrate during spawning season in coastal areas, as occur with scabbardfishes (Aphanopus spp.). We herein explore if two Aphanopus species (A. carbo and A. in...

The pattern of shell shape variation in populations of the top shell, Phorcus sauciatus from Madeira Island (NE Atlantic) was analysed as a function of substrate type and wave exposure, using geometric morphometrics. We hypothesized that P. sauciatus shows morphological variations to inhabit contrasting environments. Highly significant differences...

The interaction between bottom-up and top-down processes in coastal ecosystems has Marinebeen scarcely studied so far. Temporal changes in trophic interactions of Zostera marina along the Swedish west coast are relatively well studied, with the exception of epifaunal communities. Epifauna was used as a model study to explore resource (bottom-up) or...

The genetic polymorphism and phenotypic plasticity are key in ecology and evolution. The morphological variability of the contour of fish otoliths has been extensively used for the delimitation of stocks. These studies are conventionally based on average phenotype using elliptic Fourier analysis and lineal discriminant analysis as classifier. Consi...

Gonadal development in limpets is well-known. However, the integration of fecundity data on coastal management actions remains overlooked. Here, we use fecundity of two exploited limpets (Patella ordinaria and P. aspera) to demonstrate its potential as a conservation tool to preserve the harvested populations of both species. From October 2021 to J...

In the last decade there has been a growing interest in the Atlantic chub mackerel, Scomber colias, due to a noticeable expansion of this species in the East Atlantic Ocean from areas of greater abundance off northwest Africa to Atlantic Iberian waters and the Mediterranean Sea (ICES, 2021). To implement sustainable management measures in the curre...

Small pelagics are suitable candidates to identify regime shifts in fish stocks. They respond rapidly to ocean climate changes, specifically with a fast growth and early maturation in warm waters. This work examines landings data of small pelagics over a 40-year period (1980-2019), and auction and laboratory data of two species (Scomber colias and...

In the Madeira archipelago (NE Atlantic ocean), limpets have been harvested since the early days of colonisation, dating back to the early 15 th century. Due to the continuous long-term exploitation, the reproductive dynamics of Patella ordinaria in the Madeira archipelago is thought to have changed. The knowledge of potential fecundity is useful w...

Microbes associated with marine invertebrates play a key role in the physiological and biochemical processes of the host, and can be responsible for food-borne diseases in humans. Raw invertebrates are a common component of coastal gastronomy worldwide and their consumption could represent a potential risk to humans if their microbiome hosts infect...

Hydrodynamics are a major environmental factor on intertidal rocky shores. Morphological responses to this factor are expected to strongly influence spatial distribution of species across environmental gradients. We here analysed the shell phenotypic variability of the limpet Fissurella latimarginata using geometric morphometric analysis. The limpe...

Aims Rising sea-level following the Last Glacial Maximum lead to fragmentation of coastal limpet populations between islands of the Archipelago of Madeira. This fragmentation is reinforced by recent heavy exploitation reducing effective population size on Madeira Island. We use the limpet P. aspera to understand how the role of processes at differe...

Rising sea-level following the Last Glacial Maximum lead to fragmentation of coastal limpet populations between islands of the Archipelago of Madeira. This fragmentation is reinforced by recent heavy exploitation reducing effective population size on Madeira Island. We use the limpet P. aspera to understand how the role of processes at different ti...

Studies on microbial communities are pivotal to understand the role and the evolutionary paths of the host and their associated microorganisms in the ecosystems. Meta-genomics techniques have proven to be one of the most effective tools in the identification of endosymbiotic communities of host species. The microbiome of the highly exploited topshe...

Weight-length relationships (WLRs) are frequently used for the development of comparative studies of life history, population dynamics, ecosystem modelling and estimation of the production and biomass of populations among regions. WLRs provide information about growth, wellbeing and fitness of a population in a marine environment. WLRs for four top...

Intertidal molluscs are keystone species in intertidal rocky ecosystems often used as biological indicators of human-driven perturbations. The increasing levels of harvesting pressure on these intertidal grazers, due to the expansion of human population on coastal areas, is known to affect negatively the exploited populations by altering population...

Length-weight relationships (LWRs) provide valuable information about growth and individual fitness on the population. LWRs are commonly used in studies on life history, population dynamics, ecosystem modelling and stock assessment. A comparative study on the effect of harvesting in the relative growth of Patella aspera between Marine Protected Are...

Limpets are one of the most successful intertidal algal grazers in the north‐eastern Atlantic. They provide valuable ecosystem services, playing a pivotal role in maintaining rocky shore ecological balance and have an important economic value, being subject to high levels of exploitation in several oceanic archipelagos. Limpets represent one of the...

Intertidal and shallow subtidal molluscs are highly sensitive to overharvesting because of their restricted habitat, limited mobility and easy access to humans. Several parameters have been previously used to determine their exploitation status, e.g. sizes, abundances and reproductive stages. Herein the reproductive parameters of two exploited limp...

Hermaphroditism is thought to be an advantageous strategy common in marine molluscs that exhibit simultaneous, sequential or alternating hermaphroditism. Several species of patellid limpets have previously been shown to be protandrous hermaphrodites. The present study aimed to confirm whether this phenomenon occurs in Patella piperata. Transitional...

Topshells play a pivotal role in intertidal rocky ecosystems and are adapted to harsh thermal and hydric stress. Phorcus sauciatus , a common grazer in the Macaronesian region (Madeira and the Canaries), has rarely been studied due to its restricted geographic distribution compared with Phorcus lineatus . Monthly samples were taken throughout 2017...

Concerns on the effects of future and ongoing climate change in the terrestrial environment and open ocean have been extended to intertidal habitats. One of the consequences of climate change are the increase of intensity and frequency of hydrodynamic events (e.g., tsunamis, and increase of current and wave exposure), and consequently the increased...

Harvesting of intertidal grazers such as topshells is known to affect negatively the exploited populations by altering population structure and decreasing abundance. Phorcus sauciatus has a wide geographic distribution in the Northeastern Atlantic Ocean and is subject to increasing levels of harvesting pressure due to the expansion of human populat...

The harvesting of littoral benthic shellfish in the archipelago of Madeira dates back to the fifteenth century when the Portuguese discovered and colonized the archipelago. The consumption of littoral shellfish is part of the gastronomic cultural heritage of this region, appreciated by the local population and tourists, and has a high social and ec...

Fishing is occurring all over the globe, with an increase trend of exploiting deep stocks. Several species are currently targeted from the deep ocean, and some artisanal fisheries developed fishing gears, e.g. long-lines, with limited impact to the environment but scarce information is available on biological aspects of these exploited stocks. In t...

Intertidal limpets are subject to harvesting pressure in regions, e.g. oceanic islands, where marine organisms are a more accessible source of protein. These mollusks are very sensitive to human exploitation which often results on a decrease of their densities and an over-representation of immature individuals, because of the loss of large sized re...

The deep-sea sharks associated as by-catch of the Madeiran midwater drifting longline fishery for scabbardfishes (Aphanopus spp.) were investigated by means of an experimental survey at 800-1200 m depth within the Canary Islands Exclusive Economic Zone, whose fishing grounds have been exploited during the past 15 years. Nine species of chondrichthy...

A total of 49,151 blue jack mackerel, Trachurus picturatus, (Bowdich) were collected in Madeira Island (North-eastern Atlantic) between 2002 and 2016 to evaluate possible influence of fishing on landings and reproductive parameters. A decreasing trend in the length composition was observed over the study period and length at first maturity decrease...

The population structure of the blue jack mackerel (Trachurus picturatus, Osteichthyes, Carangi-dae), in the northeast Atlantic is still unknown. To identify any distinct population units, three areas were selected: waters off Madeira, Peniche (mainland Portugal), and the Canary Islands. Knowledge of population structure is an aspect of the populat...

This thesis addressed two main themes: the identification of the stock structure of blue jack mackerel, Trachurus picturatus (Bowdich, 1825), in the South Atlantic Northeast and the study of life history parameters for the Madeira population. The stock structure of blue jack mackerel is still unknown, and to identify the populational units, three a...

In order to evaluate the use of parasites as biological tags to identify populations of the oceanic horse mackerel, Trachurus picturatus, two samples of 100 fish each, caught off the Madeira and Canary Islands from January to June 2009, were examined for the presence of anisakids, trypanorhynchs, acanthocephalans and liver coccidians. In T. pictura...

1 Age and growth of the pink dentex Dentex gibbosus (Rafinesque, 1810) caught off the Madeira Archipelago ADRIANA ALVES & JOANA VASCONCELOS Alves, A. & J. Vasconcelos 2012. Age and growth of the pink dentex Dentex gibbosus (Rafinesque, 1810) caught off the Madeira Archipelago. Arquipelago. Life and Marine Sciences 30: 1-9. A total of 146 otoliths w...

The pelagic chub mackerel, Scomber colias Gmelin, 1789 is one of the most important fishery resources in the Madeira Archipelago. S. colias is caught by a small and coastal purse-seine fleet that traditionally operates around the islands. Monthly samples of chub mackerel were taken from commercial landings, between January 2002 and December 2005. S...

The Atlantic chub mackerel, Scomber colias Gmelin, 1789, is one of the main fisheries resources of Madeira Island. It is caught by a small and coastal purse-seine fleet that traditionally operates around the island. From January 2002 to December 2003, monthly samples of chub mackerel were collected from landings by this commercial fishing fleet. A...

The Atlantic chub mackerel, Scomber colias Gmelin, 1789, is one of the main fisheries resources of Madeira Island. It is caught by a small and coastal purse-seine fleet that traditionally operates around the island. In 2002 and 2003, monthly samples of Atlantic chub mackerel were collected from the landings of this commercial fishing fleet. A total...

Between 1984 and 1986, 630 pairs of sagitta otoliths were collected to determine the age and growth of the blue jack mackerel, Trachurus picturatus from Madeiran waters. The oldest specimen in this study was nine years old and the largest was 46 cm of total length (TL). The parameters of the von Bertalanffy growth curve were estimated for the whole...

El coccinélido Hyperaspis pantherina Fürsch, depredador específico de la cochinilla Orthezia insignis Browne, ha sido importado de Kenia y está siendo reproducido en laboratorio desde Julio de 2002 en la Isla de Madeira. Los adultos obtenidos han sido liberados sobre Jacaranda mimosifolia D. Don, árbol ornamental utilizado en las calles y jardines...