Analysis of the Adriatic macrobenthic assemblages along a spatio-temporal gradient. Habitat mapping as a tool to address restoration and recovery of marine resources

Il mare Adriatico è una delle regioni del bacino Mediterraneo più impattate poiché soggetto a multipli fattori di stress, come cambiamenti climatici e una lunga storia di intenso sfruttamento delle risorse. Allo stesso tempo ospita una grande varietà di endemismi, aree di riproduzione, nursery e foraggiamento. Il drammatico declino delle risorse target e non del mare Adriatico richiede un urgente sviluppo di nuove ed idonee misure di gestione e conservazione degli ecosistemi marini. Il cambiamento delle comunità macrobentoniche di fondo mobile può innescare un’alterazione delle reti trofiche, della qualità delle acque, del riciclo dei nutrienti. Pertanto, un’efficiente gestione degli ecosistemi marini non può prescindere dal recupero degli habitat bentonici. I risultati di questo lavoro di dottorato hanno permesso di evidenziare i principali cambiamenti avvenuti sulle comunità bentoniche dei fondali del largo del mare Adriatico (centro e nord) nel corso di circa 60 anni (1934 – 1998). Si è osservato un declino degli organismi dell’epifauna e delle specie macrobentoniche più fragili con Spugne ed Echinodermi che si sono ridotti fino ad un 90-70%. Tuttavia, lo sviluppo di modelli di preferenza degli habitat dei pennatulacei ha confermato che i fondi mobili del largo Adriatico sono habitat ideali per le specie Funiculina quadrangularis e Pennatula phosphorea. Virgularia mirabilis, invece, predilige le zone sabbiose-fangose del nord e della costa occidentale. Una dettagliata descrizione morfologica di P. phosphorea e Pteroeides spinosum è stata condotta per cercare di fornire uno strumento che possa agevolare il riconoscimento di specie ancora oggi spesso confuse a causa di descrizioni finora poco dettagliate. La tesi è stata disegnata al fine di fornire utili elementi scientifici a supporto del progetto “Adriatic Marine Ecosystem Recovery” (AMER), avente lo scopo di avviare processi utili al recupero degli ormai sovrasfruttati e degradati habitat marini del mare Adriatico.The Adriatic Sea is one of the most depleted regions of the Mediterranean Sea due to a cumulative impact of multiple stressors, such as climate change and a long history of intense exploitation. At the same time it hosts a variety of endemism, of vulnerable marine ecosystems and essential fish habitats. Severe decline of target and by-catch species call for urgent conservation measures. The ecological importance of soft bottoms macrobenthic community have been increase and their changes can lead to an alteration of food-webs, reduction of water quality, or nutrient cycling. An efficient ecosystem-based management focusing on the recovery of key benthic habitats is needed to promote recovery of stocks and to develop a sustainable exploitation of marine resources. The results of this PhD work gives a picture of the main changes occurred on macrobenthic soft bottoms communities of the north and central Adriatic Sea during 60 years (1934 – 1998). Overall change are the decline of epifauna organisms and of the most fragile macrobenthos species with sponges and echinoderms declined by 90-70% since the 1900s. However, the study of the spatial and bathymetric distribution of Adriatic sea-pens and the development of suitability habitats models have confirmed that the soft bottoms of the central offshore Adriatic Sea are favourable bottoms for Funiculina quadrangularis and Pennatula phosphorea. Virgularia mirabilis prefers the northern basin and the sandy-muddy occidental coastlines. A detailed morphological description of P. phosphorea and Pteroeides spinosum was also provided as a useful tool to sea-pens classification, usually misidentify because a lack of clear available taxonomical descriptions. The thesis has been designed in order to provide useful scientific elements to support the ‘Adriatic Marine Ecosystem Recover’ (AMER) project, which main aim is provide processes to promote recovery of depleted and overexploited fish stocks and habitats of the Adriatic Sea

Demosponge diversity from North Sulawesi, with the description of six new species

Volume: 680Start Page: 105End Page: 15

Analysis of the Adriatic macrobenthic assemblages along a spatio-temporal gradient. Habitat mapping as a tool to address restoration and recovery of marine resources

Il mare Adriatico è una delle regioni del bacino Mediterraneo più impattate poiché soggetto a multipli fattori di stress, come cambiamenti climatici e una lunga storia di intenso sfruttamento delle risorse. Allo stesso tempo ospita una grande varietà di endemismi, aree di riproduzione, nursery e foraggiamento. Il drammatico declino delle risorse target e non del mare Adriatico richiede un urgente sviluppo di nuove ed idonee misure di gestione e conservazione degli ecosistemi marini. Il cambiamento delle comunità macrobentoniche di fondo mobile può innescare un’alterazione delle reti trofiche, della qualità delle acque, del riciclo dei nutrienti. Pertanto, un’efficiente gestione degli ecosistemi marini non può prescindere dal recupero degli habitat bentonici. I risultati di questo lavoro di dottorato hanno permesso di evidenziare i principali cambiamenti avvenuti sulle comunità bentoniche dei fondali del largo del mare Adriatico (centro e nord) nel corso di circa 60 anni (1934 – 1998). Si è osservato un declino degli organismi dell’epifauna e delle specie macrobentoniche più fragili con Spugne ed Echinodermi che si sono ridotti fino ad un 90-70%. Tuttavia, lo sviluppo di modelli di preferenza degli habitat dei pennatulacei ha confermato che i fondi mobili del largo Adriatico sono habitat ideali per le specie Funiculina quadrangularis e Pennatula phosphorea. Virgularia mirabilis, invece, predilige le zone sabbiose-fangose del nord e della costa occidentale. Una dettagliata descrizione morfologica di P. phosphorea e Pteroeides spinosum è stata condotta per cercare di fornire uno strumento che possa agevolare il riconoscimento di specie ancora oggi spesso confuse a causa di descrizioni finora poco dettagliate. La tesi è stata disegnata al fine di fornire utili elementi scientifici a supporto del progetto “Adriatic Marine Ecosystem Recovery” (AMER), avente lo scopo di avviare processi utili al recupero degli ormai sovrasfruttati e degradati habitat marini del mare Adriatico.The Adriatic Sea is one of the most depleted regions of the Mediterranean Sea due to a cumulative impact of multiple stressors, such as climate change and a long history of intense exploitation. At the same time it hosts a variety of endemism, of vulnerable marine ecosystems and essential fish habitats. Severe decline of target and by-catch species call for urgent conservation measures. The ecological importance of soft bottoms macrobenthic community have been increase and their changes can lead to an alteration of food-webs, reduction of water quality, or nutrient cycling. An efficient ecosystem-based management focusing on the recovery of key benthic habitats is needed to promote recovery of stocks and to develop a sustainable exploitation of marine resources. The results of this PhD work gives a picture of the main changes occurred on macrobenthic soft bottoms communities of the north and central Adriatic Sea during 60 years (1934 – 1998). Overall change are the decline of epifauna organisms and of the most fragile macrobenthos species with sponges and echinoderms declined by 90-70% since the 1900s. However, the study of the spatial and bathymetric distribution of Adriatic sea-pens and the development of suitability habitats models have confirmed that the soft bottoms of the central offshore Adriatic Sea are favourable bottoms for Funiculina quadrangularis and Pennatula phosphorea. Virgularia mirabilis prefers the northern basin and the sandy-muddy occidental coastlines. A detailed morphological description of P. phosphorea and Pteroeides spinosum was also provided as a useful tool to sea-pens classification, usually misidentify because a lack of clear available taxonomical descriptions. The thesis has been designed in order to provide useful scientific elements to support the ‘Adriatic Marine Ecosystem Recover’ (AMER) project, which main aim is provide processes to promote recovery of depleted and overexploited fish stocks and habitats of the Adriatic Sea

Mangrove sponges from Bangka Island (North Sulawesi, Indonesia) with the description of a new species

Mangroves create unique ecological environments, furnishing a habitat opportunity for many species. The majority of published information on mangrove sponges comes from the Caribbean while few data are available from Indo-Pacific mangrove sponges. In general, species diversity of sponges in mangroves is lower than adjacent subtidal habitats in both the Caribbean and Indo-Pacific. The aim of this study is to report the first data about sponge species diversity of two mangrove forests from Bangka Island (North Sulawesi, Indonesia) and to describe a new sponge species associated with the mangroves. The survey found 19 species, belonging to 11 families and 15 genera; the samples were collected on mangrove trunks, on the roots or on the surrounding bottom. The majority of the species are typical of coral reef but two of them have been previously found only in lagoons or in mangrove habitats. These new data enlarge our knowledge about Indonesian sponges diversity and suggest the urgency to consider Indonesian mangroves as an important but underestimated element in coral reef ecological dynamics.</jats:p

Local fishers experience can contribute to a better knowledge of marine resources in the Western Mediterranean Sea

10 pages, 4 figures, 3 tables, supplementary material https://doi.org/10.1016/j.fishres.2021.106222In this study we explore fishers’ perceptions in the Ebro Delta area, Western Mediterranean, throughout structured questionnaires. Specifically, we compare the coherence of information provided by fishers with those resulting by scientific studies in terms of the status of demersal marine resources in the Ebro Delta area; we describe temporal trends of demersal key species in the area with fishers’ perceptions; and we explore the use of Local Ecological Knowledge (LEK) as an alternative data sources to reduce the gap of knowledge on the spatial distribution and temporal trends of sensitive and vulnerable benthic marine species. Our results document important changes in the bottom trawling activity in the study area and in the abundance of commercial species with time according to fishers’ perceptions. Our results mostly match quantitative information from national statistics and stock assessment analyses. In addition, we document important changes in the presence of Vulnerable Marine Ecosystems (VMEs) in the study area due to the by-catch of habitat forming species with time. According to fishers’ perceptions, habitat forming species occur in the area, but were more frequently captured incidentally in the 1980 s and 1990 s. Overall, our study evidences that fisher's perception represents an important source of complementary information to describe bottom trawling fisheries characteristics and the long-term changes of demersal target species in the Western Mediterranean Sea. Moreover, it highlights that LEK can provide fundamental and additional information on ecosystem changes and it can be a useful tool to increase the knowledge on spatial distribution and on temporal trends of vulnerable benthic speciesThis work acknowledges the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019–000928-S) to the Institute of Marine Science (ICM-CSIC). MC acknowledges partial funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 869300 (FutureMARES

Local ecological knowledge indicates temporal trends of benthic invertebrates species of the Adriatic Sea

In the Adriatic Sea, shifts in benthic community structure have been attributed to multiple stressors, from the effects of climate change to the impacts of commercial fishing. Some fishing practices, such as bottom trawling, have caused a widespread decline in exploited fish stocks. Bottom trawling is also expected to have negative impacts on benthic habitats, usually structured by and hosting a large array of invertebrate species, which provide important ecological services to fish and commercial invertebrate stocks. However, in contrast to commercial species for which long-term time series of the abundance exist, data on these habitat-forming invertebrates are scarce, as they are usually caught as bycatch and discarded. Therefore, there is great uncertainty about their long-term trends, and if these populations are stable or declining. Here we used interview surveys conducted with bottom-trawling fishers of the central Adriatic Sea to gather local ecological knowledge on megabenthos abundance occurring in their fishing domain, as an alternative source of information to conventional fisheries data. We interviewed 44 fishers, from the most important ports of the Marche region of Italy, to understand how megabenthic species have changed in abundance within the area since the 1980s. Specifically, we asked fishers to provide qualitative abundance scores for 18 invertebrate species in five phyla (Porifera, Cnidaria, Bryozoa, Mollusca, and Echinodermata) based on their recollection of these species' presence in bycatch. We stratified responses in homogeneous temporal periods and geographic sectors of the study area, and analyzed their response with mixed effect ordered logistic regression models in order to evaluate spatiotemporal changes in the perceived abundance of each species. Our analysis suggests that the abundance of the sponge Geodia cydonium, the molluscs Pecten jacobaeus, Atrina fragilis, Neopycnodonte cochlear, and the group of holothurians, have declined. From fishers' perceptions, only the bryozoan Amathia semiconvoluta has increased. Local ecological knowledge can provide important information on environmental change and can highlight species and ecosystems at risk when conventional scientific data are scarce or absent. This approach can be expanded to other regions of the Adriatic and broader Mediterranean Sea to reconstruct change of this heavily exploited marine region

Sea pens in the Mediterranean Sea: habitat suitability and opportunities for ecosystem recovery

Abstract The aim of this study is to synthesize available information on sea pens in the Mediterranean Sea and fill existing knowledge gaps through modelling of suitable habitat, with the overarching goal of informing strategies for protecting sea pen habitats from trawling impacts and facilitating their recovery. A review spanning the last 30 years was conducted to map the distribution of Mediterranean sea pen species. In the Adriatic Sea, presence–absence data were modelled with generalized additive models (GAMs) to identify potentially suitable habitats for Funiculina quadrangularis, Virgularia mirabilis, and Pennatula spp. Results show that sea pen distribution in the Mediterranean is mainly limited to continental northern shelves. Six species have been recorded throughout the Adriatic basin, where habitat suitability models confirm that its soft bottoms yield favourable conditions for sea pen assemblages. This information can help guide strategies for diminishing and reversing the impacts of bottom trawling on these vulnerable habitats.</jats:p