Density dependence in marine protected populations: a review

The cessation or reduction of fishing in marine protected areas (MPAs) should promote an increase in abundance and mean size and age of previously exploited populations. Thus density-dependent changes in life-history characteristics should occur when populations are allowed to recover in MPAs. In this review, we synthesize the existing information on resource limitation in marine ecosystems, density-dependent changes in life-history traits of exploited populations and evidence for biomass export from MPAs. Most evidence for compensatory changes in biological variables has been derived from observations on populations depleted by high fishing mortality or on strong year classes, but these changes are more evident in juveniles than in adults and in freshwater rather than in marine systems. It is unclear if adults of exploited marine populations are resource limited. This may suggest that exploited populations are controlled mainly by density-independent processes, which could be a consequence of the depleted state of most exploited populations. MPAs could be a useful tool for testing these hypotheses. If we assume that resources become limiting inside MPAs, it is plausible that, if suitable habitats exist, mobile species will search for resources outside of the MPAs, leading to export of biomass to areas which are fished. However, it is not possible to establish from the available data whether this export will be a response to resource limitation inside the MPAs, the result of random movements across MPA boundaries or both. We discuss the implications of this process for the use of MPAs as fisheries management tools.Financial support was provided by the EU CEC DGXII – MAST III contract number: MAS3-ct97-0155

Parasite communities of the white seabream Diplodus sargus sargus in the marine protected area of Medes Islands, north-west Mediterranean Sea

Marine protected areas are considered a useful tool to preserve and recover the biodiversity of ecosystems. It is suggested that fisheries not only affect populations of target and bycatch species but also their parasite communities. Parasites can indicate fishery effects on host species and also on the whole local community, but the effects of fisheries and protection measures on parasite communities are relatively unknown. This study analyses parasite communities of the white seabream Diplodus sargus sargus in order to assess potential effects exerted by protection measures within and by fisheries outside a reserve in the western Mediterranean Sea. This small scale analysis offered the opportunity to study different degrees of fishery effects on parasite infracommunities, without considering climatic effects as an additional factor. Parasite infracommunities of fishes from the no-take zone (NTZ) differed in their composition and structure compared with areas completely or partially open to fisheries. The detected spatial differences in the infracommunities derived from generalist parasites and varied slightly between transmission strategies. Monoxenous parasites were richer and more diverse in both fished areas, but more abundant in the notake, whereas richness and abundance of heteroxenous parasites were higher for the NTZ. In addition to host body size as one factor explaining these spatial variations, differences within parasite infracommunities between the areas may also be linked to increased host densities and habitat quality since the implementation of the NTZ and its protection measures

Density dependence in marine protected populations: A review

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A baited underwater video technique to assess shallow water Mediterranean fish assemblages: methodological evaluation

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PENERAPAN MODEL PEMBELAJARAN DISCOVERY LEARNING PADA MATERI EKOSISTEM UNTUK MENINGKATKAN KETERAMPILAN PROSES SISWA KELAS VIIB SMPN 2 KOTA BENGKULU PENELITIAN TINDAKAN KELAS

Penelitian ini bertujuan untuk memperoleh gambaran dari penerapan model discovery learning yang dilakukan oleh guru dan gambaran keterampilan proses siswa kelas VIIB SMPN 2 Kota Bengkulu. Jenis penelitian ini adalah penelitian tindakan kelas yang dilakukan dalam dua siklus. Setiap siklus penelitian ini terdiri atas empat tahap yaitu perencanaan, pelaksanaan, pengamatan, refleksi. keterampilan proses yang di teliti adalah keterampilan kelompok siswa dalam melakukan penyelidikan yang dilihat pada tahap identifikasi masalah, pengumpulan data, pengolahan Data, dan menarik kesimpulan yang diukur dengan indikator mengamati, mengklasifikasi, menginferensi dan mengkomunikasikan hasil penyelidikan secara lisan dengan menggunakan lembar keterampilan proses. Pembelajaran biologi menggunakan model discovery learning pada penelitian ini adalah kegiatan guru pada tahapan identifikasi masalah, pengumpulan data, pengolahan data, dan menarik kesimpulan yang diukur dengan lembar observasi. Hasil penelitian menunjukan bahwa pembelajaran tergolong baik dari siklus I dengan rerata 35,5 ke siklus II dengan rerata 36,5. Kegiatan guru yang belum optimal pada siklus I telah diperbaiki pada siklus II namun masih ada kegiatan yang belum optimal di siklus II yaitu memonitor siswa menyimpulkan hasil pengamatan dan merespon pertanyaan siswa saat menyimpulkan hasil pengamatan dengan pertanyaan penuntun di tahap menarik kesimpulan. Keterampilan proses siswa pada siklus I tergolong baik dengan rerata skor 3,13 dan meningkat pada siklus II dengan rerata skor 3,50. Kesimpulannya dengan menggunakan model discovery learning dapat meningkatkan keterampilan proses siswa. Kata kunci: Discovery Learning, Keterampilan Proses, Biologi SM

Location of the Mediterranean marine protected areas (MPAs) studied.

<p>1: Carry-le-Rouet, 2: Banyuls, 3: Medes, 4: Cabrera, 5: Tabarca, 6: Cabo de Palos.</p

Abundance, biomass and mean weight of the three species of groupers, <i>E. marginatus</i>, <i>E. costae</i> and <i>M. rubra</i> according to the tree levels of protection (No-take zone: NTZ, Buffer zone: BZ and unprotected: UP) in all MPAs studied (BAN: Banyuls; MED: Medes; CAB: Cabrera; TAB-r: Tabarca Rocky habitat; TAB-p: Tabarca <i>Posidonia</i> habitat; CP: Cabo de Palos), Carry excepted as no groupers were recorded there.

<p>Abundance, biomass and mean weight of the three species of groupers, <i>E. marginatus</i>, <i>E. costae</i> and <i>M. rubra</i> according to the tree levels of protection (No-take zone: NTZ, Buffer zone: BZ and unprotected: UP) in all MPAs studied (BAN: Banyuls; MED: Medes; CAB: Cabrera; TAB-r: Tabarca Rocky habitat; TAB-p: Tabarca <i>Posidonia</i> habitat; CP: Cabo de Palos), Carry excepted as no groupers were recorded there.</p

Hypotheses for the shape of gradient of fish biomass across MPA boundaries with raw data (solid line) and residual data after extracting habitat influence (dotted line) where habitat quality (a) is equally good or (b) has no influence both inside and outside the MPA, and (c) where habitat quality is better within the MPA.

<p>The vertical line indicates the limit of the MPA, with protected area to the left and fishes zones to the right.</p

Permutational multivariate analysis of variance (PERMANOVA) results for abundance, biomass and mean weight of <i>E. marginatus</i> found in the locations studied on Western Mediterranean Sea where groupers are present both inside and outside the MPA.

<p>L: locality, S: sector, Z: zone, P: protected, UP: unprotected, res: residuals, df: degree-of-freedom, MS: mean square, PF: pseudo-F, p: significance level (bold characters are used for significant results). CAB – Cabrera; TAB-r – Tabarca rocky habitat; CP – Cabo de Palos.</p

Analysis of deviance for the generalised additive models (GAMs) fitted with raw data and residuals of multiple linear regressions with habitat variables on biomass of the three studied grouper species.

<p>Analysis of deviance for the generalised additive models (GAMs) fitted with raw data and residuals of multiple linear regressions with habitat variables on biomass of the three studied grouper species.</p