ClimateFish: A Collaborative Database to Track the Abundance of Selected Coastal Fish Species as Candidate Indicators of Climate Change in the Mediterranean Sea

Under the effects of global warming, many animals and plants are undergoing rapid distribution shifts. These changes can be particularly rapid in marine fishes, and many species have responded markedly to recent increases in sea temperature. ClimateFish is an open-access database, which collates abundance data for 7 Mediterranean indigenous and 8 non-indigenous fishes, proposed as candidate indicators of climate change. These species have been selected by a network of Mediterranean scientists based on their wide distribution, responsiveness to temperature conditions and easy identification. Data are periodically collected according to a standard visual census protocol in four different depth layers. At present, the database collates data on a total number of 101'771 observed individuals belonging to the 15 target species. Counts were realized along 3142 transects carried out in 7 Mediterranean countries between 2009 and 2021. This database, associated with climate data, offers new opportunities to investigate spatiotemporal effects of climate change and to test the effectiveness of each selected indicator. Data are available at https://doi.org/10.17882/86784.The Mediterranean ClimateFish initiative was initially conceived by the international basin wide monitoring program CIESM Tropical Signals (funded by the Albert II of Monaco Foundation) and subsequently supported by the Interreg Med Programme (Projects: MPA-ADAPT, grant number 1MED15_3.2_M2_337 and MPA Engage, grant number 5MED18_3.2_M23_007), 85% co funded by the European Regional Development Fund

Tracking Signals of Change in Mediterranean Fish Diversity Based on Local Ecological Knowledge

One of the expected effects of global change is increased variability in the abundance and distribution of living organisms, but information at the appropriate temporal and geographical scales is often lacking to observe these patterns. Here we use local knowledge as an alternative information source to study some emerging changes in Mediterranean fish diversity. A pilot study of thirty-two fishermen was conducted in 2009 from four Mediterranean locations along a south-north gradient. Semi-quantitative survey information on changes in species abundance was recorded by year and suggests that 59 fish species belonging to 35 families have experienced changes in their abundance. We distinguished species that increased from species that decreased or fluctuated. Multivariate analysis revealed significant differences between these three groups of species, as well as significant variation between the study locations. A trend for thermophilic taxa to increase was recorded at all the study locations. The Carangidae and the Sphyraenidae families typically were found to increase over time, while Scombridae and Clupeidae were generally identified as decreasing and Fistularidae and Scaridae appeared to fluctuate in abundance. Our initial findings strongly suggest the northward expansion of termophilic species whose occurrence in the northern Mediterranean has only been noted previously by occasional records in the scientific literature

The role of rock substratum in the ecology of intertidal epilithic biofilms

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

The role of rock substratum in the ecology of intertidal epilithic biofilms

The overall aim of this thesis was to investigate the role of the underlying rock type on the ecology of epilithic biofilms in relation to other major regulating factors such as season, shore height and grazing.  In Chapter 1 the relevant literature has been reviewed covering the development and succession of biofilms and describing their importance to the ecology of rocky shore habitats.  The aims and rationale of the thesis are then outlined. In Chapter 2 a broadscale survey of microbial biomass and assemblage composition was made at sites along the south coast of England from Lands End to the Isle of Wight.  This encompassed shores of chalk, limestone, sandstone old red sandstone and granite sampled at a range of spatial scales (10’s km to 10’s cm) in an hierarchical design with two shores of each rock type and two tidal levels on each shore.  Microbiota were quantified using extracted chlorophyll to provide an index of biomass and scanning electron microscopy to visualise microbial assemblages.  Microalgal biomass was greater on soft, porous carbonate rocks such as chalk and limestone than on hard, impermeable quartz-based rocks such as granite and old red sandstone.  These differences were significant in the early spring and summer.  However, they were most apparent in early spring and the in upper eulittoral rather than the littoral fringe. Local effects of rock type were investigated by comparing microbial films on rocks with contrasting physical and chemical properties that were present at the same shores (Chapter 3). Chalk and flint were compared at Freshwater Bay and Culver Cliff on the Isle of Wight, limestone and chert at Portland Bill, and dolomite and oil shale at Kimmeridge.  Microbial biomass tended to be greater on carbonate rocks than on quartz based rock but this effect was only significant contrasts between dolomite and oil shale.</p

Most important fish taxa in typifying the groups ‘I’ and D by SIMPER analysis.

<p>List of fish taxa in decreasing order of their importance in typifying the groups ‘INCREASE’ (‘I’) and ‘DECREASE’ (‘D’) by SIMPER analysis performed on presence/absence data. Cut off for low contributions: 90.00%. Group ‘I’ average similarity 18.05; Group ‘D’ average similarity 12.51; Group ‘F’ average similarity 15.44.</p><p>*Milazzo,</p>§<p>Linosa and Lampedusa.</p

List of fish taxa cited by the respondents.

<p>The number of times in which they were assigned to the groups ‘INCREASE’ (‘I’), ‘DECREASE’ (‘D’) and ‘FLUCTUATE’ (‘F’) is reported.</p

Study locations in the Mediterranean Sea.

<p>Study locations in the Mediterranean Sea.</p

Percent distribution of fishing methods adopted by the respondents.

<p>Interviewed (Tot N = 32) were both recreational (N = 8, 25%) and professional (N = 24, 75%) fishermen.</p

PERMANOVA Analysis.

<p>Permutational multivariate analysis of variance based on the Euclidean dissimilarity measure for presence-absence data. The test was done using 9999 permutations under the reduced model. The group ‘FLUCTUATE’ was excluded from the analysis.</p