The role of grazers in early-life stages of Cystoseira sensu lato can be crucial in the restoration of marine forests

Grazing is one of the most important biological factors controlling the abundance of early-life stages of fucoids and one of the major issues when restoring marine forests. Benthic macroinvertebrates (e.g., sea urchins) and fish shape and regulate benthic macroalgal communities from polar to tropical regions and can be responsible for regime shifts leading to the predominance of turfs and/or barren grounds. However, other herbivores (i.e., mesograzers) could also significantly participate in the grazing, especially on early-life stages, hampering the persistence and capacity of Cystoseira sensu lato populations to recover after major disturbances and being a cause of failure of restoration actions. We performed experiments in the field and in mesocosm in order to investigate the herbivory pressure and the effects of different grazers on recruits of Cystoseira compressa. The results highlight that non-strict herbivorous invertebrates, such as Clibanarius erythropus, Cerithium vulgatum, and Idotea balthica, graze on recruits of Cystoseira s.l. spp., with I. balthica showing the highest consumption rate. We concluded that biotic factors such as herbivory, which affect key life stages, can be crucial for the conservation of Cystoseira s.l. forests and need to be better understood and considered on a case-by-case basis when planning restoration actions

Inventaire et cartographie des peuplements de Fucales du Parc National de Port-Cros

En Méditerranée, les algues brunes du genre Cystoseira C. Agardh et Sargassum C. Agardh sont les principaux représentants de l’ordre des Fucales Kylin. La plupart des espèces sont endémiques de Méditerranée et se développent de la zone infralittorale à la zone circalittorale supérieure (Giaccone et Bruni 1973). Ces espèces sont considérées comme des espèces fondatrices (sensu Bruno et al. 2001). En effet, de port dressé, certaines peuvent atteindre plusieurs dizaines de centimètres de haut et ainsi former de vastes populations pérennes qui structurent en trois dimensions les substrats rocheux et abritent sous leurs canopées une diversité élevée de faune et de flore (Sauvageau 1912 ; Funk 1927 ; Rull et Gómez-Garetta 1990 ; Ballesteros 1992 ; Ballesteros et al. 1998). Certaines espèces de Cystoseira sont les espèces dominantes de plusieurs communautés benthiques (Feldmann 1937a,b ; Molinier 1958 ; Pignatti 1962, Giaccone 1973; Giaccone et Bruni 1973; Verlaque 1987; Ballesteros 1990a,b). Dans certaines régions de la Méditerranée, des régressions importantes de populations de Cystoseira et de Sargassum ont été observées. Ces régressions ont des causes diverses : pollution (Bellan Santini 1966, 1968; Belsher 1977; Munda 1974, 1982; Hoffmann et al. 1988; Rodríguez-Prieto & Polo 1996; Soltan 2001, Soltan et al. 2001), surpâturage par des herbivores (Gros 1978; Vukovic 1982; Verlaque 1987; Arrighi 1995; Sala et al., 1998; Hereu 2004), compétition pour l’espace avec les bancs de moules (Gros, 1978), augmentation de la turbidité (Cormaci et Furnari 1999). Certaines Fucales sont classées parmi les végétaux en danger de Méditerranée (PNUE 1990)..

Does arthrodesis of the first metatarsophalangeal joint correct the intermetatarsal M1M2 angle? Analysis of a continuous series of 208 arthrodeses fixed with plates

INTRODUCTION: First-ray metatarsophalangeal arthrodesis is a classic surgical procedure in the treatment of severe hallux valgus, hallux rigidus, revision surgery, and inflammatory arthritis. The objective of this study was to verify if metatarsophalangeal plate arthrodesis could correct the M1M2 intermetatarsal angle. MATERIAL AND METHODS: This prospective and continuous series (June 2007 to March 2011) included 208 patients (48% severe and/or arthritic hallux valgus, 18% hallux rigidus, 16% rheumatoid forefoot, 13% surgical revision of the first ray, 5% hallux varus), with a mean age of 62.4±9.9 years (range, 19-87 years). All the patients were operated on by a senior surgeon with the same technique: spherical avivement of the joint surfaces using reamers, osteosynthesis with an anatomic plate (Fyxis-BiotechTM) in Ti.6Al.4 V alloy prebent to 5° with a phalangeal arm to receive an oblique metatarsophalangeal screw in compression, in addition to four 2.7-mm nonlocking dorsal screws. The full-scale preoperative and intraoperative angle measurements were taken on AP and lateral X-rays of the weightbearing foot, as related to the etiology and the severity of the preoperative metatarsus varus (M1M

Effects of reserve protection level on the vulnerable fish species Sciaena umbra and implications for fishing management and policy

International audienceThe brown meagre Sciaena umbra, an iconic demersal fish species in Mediterranean coastal habitats, is particularly vulnerable to fishing pressure and presents a worrying population decline. Fish numbers and sizes were surveyed by visual census at Scandola (Corsica) in and outside reserve zones subject to increasing levels of protection, including unprotected zones (UP) where all fishing activities are permitted, buffer zones (BZ) subject to partial protection and a totally protected no-take integral reserve zone (IR). The numerical abundance, individual size and biomass of the brown meagre were found to increase with levels of reserve protection. The abundance of the larger size classes and the numbers of fish per shoal were significantly lower in unprotected zones. A comparison with similar censuses performed in 1983 showed a significant increase of S. umbra abundance in IR, but no difference in UP. That increasing levels of protection resulted in increased abundance and biomass of the brown meagre suggested a prominent role of fishing, particularly spearfishing, activities in the persistence of its low abundance in the unprotected zones. As a consequence, protective action for the brown meagre (including a ban on both spearfishing and recreational hook-and-line fishing) has been introduced in France since January 2014

Does Arthrodesis of the First Metatarso-Phalangeal Joint Correct the Intermetatarsal M1M2 Angle? Analysis of Continuous Series of 208 Arthrodesis Plate-Osteosyntheses

Category: Midfoot/Forefoot Introduction/Purpose: MTP-1 arthrodesis allows effective correction of both inter-metatarsal M1M2 and M1P1 angles. Undercorrection of wide M1M2 angle after MTP-1 arthrodesis causes persistently wide forefoot, metatarsalgia and unaesthetic gap between first and second toes. In severe deformities, Rippstein recommended supplementary first metatarsal osteotomy or cuneo-metatarsal arthrodesis. The present study sought to investigate correction of inter-metatarsal M1M2 angle after MTP-1 arthrodesis according to aetiology and pre-operative deformity severity. Methods: A prospective continuous series (June 2007- March 2011) included 208 patients: 48% severe hallux valgus and/or osteoarthritis, 18% hallux rigidus, 16% rheumatoid osteoarthritis, 13% revision, 5% hallux varus; mean age, 62.4±9.9 years (19-87 years). All patients were operated on by a single senior surgeon with the same technique: articular surface reaming (cup-ball), osteosynthesis with titanium anatomical plate (Fyxis-Biotech) and the same rehabilitation procedure. Pre- and post-operative hallux positions were analysed on antero-posterior and lateral weightbearing views. M1M2 and M1P1 were measured according to American Orthopaedic Foot and Ankle Society guidelines. Results: Mean follow-up was 18.6±12.4 months; fusion rate, 97%; 5% plate removal. Mean M1P1 angle was 33.8±19.7° (-45° to 67°) preoperatively, and 13.4±5.3° (0-32°) at follow-up; M1M2, 14.2±5.4° (0° to 26°) and 6.5± 2.3° (0-12°) respectively. M1M2 angle was 10° in only 2 patients (0.9%) associated with cuneometatarsal osteoarthritis. Improvement increased with severity of preoperative M1M2 angle (p 10°. Pydah correlated preoperative and postoperative intermetatarsal angle with a regression line, without recommending any secondary procedure to improve M1M2 angle. In severe increased preoperative M1M2 angle, we do not recommend associating systematic C1M1 arthrodesis or basal metatarsal osteotomy to MTP-1 arthrodesis, but suggest that additional basal metatarsal osteotomy or C1M1 fusion might be required only in exceptional associated degenerative C1M1 joint

Inventaire et cartographie des peuplements de Fucales du Parc National de Port-Cros

En Méditerranée, les algues brunes du genre Cystoseira C. Agardh et Sargassum C. Agardh sont les principaux représentants de l’ordre des Fucales Kylin. La plupart des espèces sont endémiques de Méditerranée et se développent de la zone infralittorale à la zone circalittorale supérieure (Giaccone et Bruni 1973). Ces espèces sont considérées comme des espèces fondatrices (sensu Bruno et al. 2001). En effet, de port dressé, certaines peuvent atteindre plusieurs dizaines de centimètres de haut et ainsi former de vastes populations pérennes qui structurent en trois dimensions les substrats rocheux et abritent sous leurs canopées une diversité élevée de faune et de flore (Sauvageau 1912 ; Funk 1927 ; Rull et Gómez-Garetta 1990 ; Ballesteros 1992 ; Ballesteros et al. 1998). Certaines espèces de Cystoseira sont les espèces dominantes de plusieurs communautés benthiques (Feldmann 1937a,b ; Molinier 1958 ; Pignatti 1962, Giaccone 1973; Giaccone et Bruni 1973; Verlaque 1987; Ballesteros 1990a,b). Dans certaines régions de la Méditerranée, des régressions importantes de populations de Cystoseira et de Sargassum ont été observées. Ces régressions ont des causes diverses : pollution (Bellan Santini 1966, 1968; Belsher 1977; Munda 1974, 1982; Hoffmann et al. 1988; Rodríguez-Prieto & Polo 1996; Soltan 2001, Soltan et al. 2001), surpâturage par des herbivores (Gros 1978; Vukovic 1982; Verlaque 1987; Arrighi 1995; Sala et al., 1998; Hereu 2004), compétition pour l’espace avec les bancs de moules (Gros, 1978), augmentation de la turbidité (Cormaci et Furnari 1999). Certaines Fucales sont classées parmi les végétaux en danger de Méditerranée (PNUE 1990)..

Depth-dependant response to light of the reef building coral, Pocillopora verrucosa: implication of oxidative stress

Several environmental factors have been described to trigger bleaching in cnidarian/dinoflagellate endosymbiosis. However, the molecular mechanisms underlying this process still need more investigations. Symbiosis breakdown is known to result from physiological damage to animal host cells and/or symbionts. Cellular oxidation appears to be an essential player in this damage. Indeed, oxidative stress is a direct consequence of increase in irradiance and temperature, the two main environmental factors involved in bleaching. In this study, we examined the role of irradiance in inducing dissociation and oxidative stress in cnidarians and dinoflagellates. We used the bleaching-sensitive scleractinian coral Pocillopora verrucosa in a field cross-transplantation experiment performed between 5 m and 20 m depth at Grande Glorieuse Island (Indian Ocean), a preserved area subject to minimal anthropogenic influence. Cellular damage and increase in antioxidant defense were correlated with bleaching in upward transplanted samples. Downward transplanted colonies presented no associated alterations similar to the controls. We therefore conclude that increasing light induced bleaching via a prooxidative period. Remarkably, the distribution of Symbiodinium over depth was invariant; all colonies were monomorph for clade C, suggesting that bleaching sensitivity of P. verrucosa might not be associated with clade specificity

Occurrence of the toxic dinoflagellate Ostreopsis cf. ovata in relation with environmental factors in Monaco (NW Mediterranean)

To study environment characteristics favoring the toxic benthic dinoflagellate Ostreopsis cf. ovata, a survey was conducted in Monaco (NW Mediterranean Sea), in summers 2007 and 2008. Epiphytic and planktonic blooms occurred almost simultaneously and a high variation of abundances at low spatial scales was observed. An early and very marked bloom occurred in 2007, compared to a later and less abundant development in 2008. These distinct patterns in bloom timing corresponded with very different hydroclimatic scenarios in 2007 (hot spring and relatively cold summer) and 2008 (standard year compared to the median year profile estimated with data from 1995 to 2008). No clear impacts of summer seawater temperature, rainfall or nutrient concentrations were evident. Strong wind may favor the dispersal of benthic and planktonic cells. Our study suggests that further investigations are needed to examine the potential role of Ostreopsis nutritional mode (i.e. autotrophy vs. mixotrophy)

Occurrence of a lost fishing net within the marine area of the Port-Cros national Park (Provence, northwestern Mediterranean Sea). Sci. Rep. Port-Cros natl. Park, 26 : 109-118.

Sci. Rep. Port-Cros natl. Park, 26 : 109-118.not availabl

Juvenile fish assemblages in temperate rocky reefs are shaped by the presence of macro-algae canopy and its three-dimensional structure

International audienceArborescent macro-algae forests covering temperate rocky reefs are a known habitat for juvenile fishes. However, in the Mediterranean, these forests are undergoing severe transformations due to pressures from global change. In our study, juvenile fish assemblages differed between pristine arborescent forests (Cystoseira brachycarpa var. balearica) versus an alternate state: bushland (Dictyotales – Sphacelariales). Forests hosted richer and three-fold more abundant juvenile assemblages. This was consistent through space, whatever the local environmental conditions, along 40 km of NW Mediterranean subtidal rocky shores (Corsica, France). Among Cystoseira forests, juvenile assemblages varied through space (i.e. between localities, zones or sites) in terms of total abundance, composition, richness and taxa-specific patterns. More than half of this variability was explained by forest descriptors, namely small variations in canopy structure and/or depth. Our results provide essential cues for understanding and managing coastal habitats and fish populations. Further studies are needed to explain the residual part of the spatial variability of juvenile fish assemblages and to help focus conservation efforts