Abundance, community composition, and differential habitat associations of fishes along a Mediterranean Marine Protected Area gradient Anthony Marshak and Shanna Madsen

Outline Introduction Objectives Methodology The usual suspects Results Conclusions

Marine Protected Areas Coastal fish resources – Over-exploited – May not be sustainable MPAs – High biodiversity – Replenish exploited species stocks – Protect nursery and recruitment habitats – Spill-over effect

Tabarca Alicante, Spain (1986) – 4km, 1400ha Artisanal fisheries – Serranidae species (grouper, wreckfish, bass) and Sparidae (common dentex, seabream) – Low tech, not low impact Increases in many species – common dentex, dusky grouper, common and annular seabream (Mas and Barcala 1997) – spillover effect : common dentex, brown meagre, various wrasses (Forcada et al. 2009)

Three management zones – Tabarca III Pelagic trap nets, swimming, mooring, and diving are allowed – Tabarca II Pelagic trap nets, no swimming etc. – Tabarca I Only scientific research allowed Tabarca

Objectives 1. Describe species assemblages and differences in fish abundance between Tabarca (II and III) marine reserve, as well as Santa Pola and Cabo de las Huertas (unprotected) 2. Determine and evaluate differences in abundance and species composition over a gradient of Posidonia oceanica coverage – 0 to 30% Posidonia per transect = low – 30 to 69% Posidonia per transect = medium – 70 to 100% Posidonia per transect = high

Study Sites/Experimental Design Eric Sparks

Study Sites/Experimental Design 6 Posidonia transects 6 rocky macroalgae transects Total Santa Pola transects=12

Study Sites/Experimental Design 3 Posidonia transects 3 rocky macroalgae transects Total Cabo de las Huertas transects=6

Study Sites/Experimental Design

6 Posidonia transects 6 rocky macroalgae transects Total Tabarca III transects=12

Study Sites/Experimental Design 6 Posidonia transects 6 rocky macroalgae transects Total Tabarca II transects=12

Methodology Transects – 50m x 2m – waypoints Fish counts – Identified/quantified in 5m intervals – Benthic habitat classified Becky Gericke

Boops boops

Chromis chromis

Oblada melanura

Coris julis

Diplodus spp. D. vulgaris D. puntazzo D. annularis D. sargus

Mullus surmuletus

Sarpa salpa

Symphodus tinca

LocationSampling DatesSitesTransects Santa Pola3, 9-10 Sept, Tabarca II4 Sept, Tabarca III8 Sept, Cabo de las Huertas10 Sept, *Performed a total of 42 transects (50x2 meters) within 9 sites *Cabo de las Huertas and Posidonia habitats of Santa Pola are listed as Lugar Interes Comunitario (LIC) sites *Observed 23 species and 4929 individuals

*Highest density at Tabarca II (Isla Nao) *Tabarca III Site density < Cabo de Las Huertas Site Overall average density of fishes (number / m 2 ) per site

Demersals All Fishes SourceDFSum of squaresMean squaresFPr > F Model Error Corrected Total SourceDFSum of squaresMean squaresFPr > F Location < Proportion Posidonia Location*Prop. Posidonia way ANOVA All Fishes SourceDFSum of squaresMean squaresFPr > F Model Error Corrected Total SourceDFSum of squaresMean squaresFPr > F Location < Proportion Posidonia Location*Prop. Posidonia way ANOVA Demersals Average Density (Number of fish / m 2 )

*Examine densities independent of transect in weighted average per habitat (Total number of fishes / total surveyed area) *Visual trend confirms importance of Posidonia/rock; rock/macroalgae habitats *Increased abundance within Posidonia habitat in Tabarca II and III sites

Density Per Fish Family

Conclusions Significant difference in fish abundance throughout the protected and unprotected regions, but no significance for Posidonia proportion – Suggests that degree of protection of the entirety is a driving factor and that protection of all habitats should be incorporated in marine reserves – Additionally, for demersal species, the increase in abundance is more pronounced in the protected areas – Species richness and density highest in Tabarca II

Conclusions Mixed habitats of Posidonia oceanica and rock, or structured rock and macroalgae appear to be critical habitats to most demersal species than strictly homogenous Posidonia Cabo de las Huertas appears to be less impacted than Santa Pola in terms of availability of habitat and density of pelagic and demersal fishes

Conclusions Continued protection and enforcement of the Tabarca marine reserve will work to enhance biodiversity and conserve essential habitat These data show the importance of marine reserves and protection of heterogeneous habitats in the promotion of increased diversity and abundance of Mediterranean fish communities.

Thank you! Dr. Jose Luis Sanchez Lizaso Dr. Jose Luis Sanchez Lizaso Dr. Just Cebrian Dr. Just Cebrian Dr. Ken Heck Dr. Ken Heck Dr. Alfonzo Ramos Dr. Alfonzo Ramos Felio Lozano Quijada Felio Lozano Quijada Department of Marine Sciences (USA) Department of Marine Sciences (USA) CIMAR graduate students and staff CIMAR graduate students and staff