Recreational fisheries in Portofino Marine Protected Area,Italy: Some implications for the management

Since the 1970s, recreational fishing has become a mass hobby in Italy, reaching a large number of people, who, using modern equipment, increased their harvesting capacity, provoking serious conflicts with the professional fisheries. Recreational fishing is strictly regulated inside Italian Marine Protected Areas (MPAs) and is generally allocated to local residents, mainly to reduce the tensions caused by limitations of access to the resources. The aim of this study was to provide an analysis of recreational fishing activities within the Portofino MPA (Mediterranean Sea), to assess the possible impact on the local fish stocks and to plan potential management actions. Furthermore, some serious inconsistencies on the minimum lengths of fish caught as defined by law relative to the minimum size of first reproduction are discussed. Since 2014, all anglers exploiting the Portofino MPA have been obliged to fill out a logbook. The compilation of these was not completely satisfactory, when compared with a group of reliable anglers whose catches were accurately monitored, but allowed for estimated yields of about 24 kg/angler/yr. After 15 years of protection, the fish biomass has increased within the Portofino MPA, generating a positive spillover effect. At the same time, it has attracted many anglers whose gross harvesting was estimated at about 8 t/year, representing about the 8% of the total yield of the local small‐scale fishery.     

辽宁海洋牧场建设的金融投入研究

辽宁省海洋资源丰富,渔业产业基础雄厚,具有发展海洋牧场的巨大潜力。辽宁海洋牧场的技术密集型和资金密集型特征,需要构建有力、有效的金融服务体系。为此,需要发挥政策金融的引领作用,突出商业金融的中坚作用,注重合作金融的普惠作用,形成整体合力。     

海洋灾害对渔业资源管理的影响及其对策

近年来,恶性捕捞严重,海洋渔业资源管理模式落后。同时,人类过度开发利用以及不可抗因素时有发生,使得海洋生态系统遭到破坏,渔业资源管理也面临着新的问题。对我国渔业资源管理现状以及非常态下渔业资源的恢复与开发利用等方面进行了综述,对非常态下渔业资源管理中存在的问题进行了阐述,并提出了对应的管理措施,最后对非常态下渔业资源管理制度发展建设进行了展望。     

Water quality dynamics and shrimp (Litopenaeus vannamei) production in intensive, mesohaline culture systems with two levels of biofloc management

A dense microbial community develops in the water column of intensive, minimal-exchange production systems and is responsible for nutrient cycling. A portion of the microbial community is associated with biofloc particles, and some control over the concentration of these particles has been shown to provide production benefits. To help refine the required degree of control, this study evaluated the effects of two levels of biofloc management on water quality and shrimp (Litopenaeus vannamei) production in commercial-scale culture systems. Eight, 50 m³ raceways were randomly assigned to one of two treatments: T-LS (treatment-low solids) and T-HS (treatment-high solids), each with four replicate raceways. Settling chambers adjacent to the T-LS raceways had a volume of 1700 L with a flow rate of 20 L min⁻¹. The T-HS raceways had 760 L settling chambers with a flow rate of 10 L min⁻¹. Raceways were stocked with 250 shrimp m⁻³, with a mean individual weight of 0.72 g, and shrimp were grown for thirteen weeks. Raceways in the T-LS treatment had significantly reduced total suspended solids, volatile suspended solids, and turbidity compared to the T-HS treatment (P ≤ 0.003). The T-LS raceways also had significantly lower nitrite and nitrate concentrations, and the T-HS raceways had significantly lower ammonia and phosphate concentrations (P ≤ 0.021). With the exception of nitrate, there were no significant differences between the change in concentration of water quality parameters entering and exiting the settling chambers in the T-LS versus the T-HS treatment. Nitrate never accumulated appreciably in the T-LS raceways, possibly due to denitrification in the settling chambers, bacterial substrate limitations in the raceways, or algal nitrate assimilation. However, in the T-HS raceways nitrate did accumulate. The T-HS settling chambers returned a significantly lower nitrate concentration and significantly greater alkalinity concentration than what entered them (P ≤ 0.005), indicating that denitrification may have occurred in those chambers. There were no significant differences in shrimp survival, feed conversion ratio, or final biomass between the two treatments. However, shrimp in the T-LS treatment grew at a significantly greater rate (1.7 g wk⁻¹ vs. 1.3 g wk⁻¹) and reached a significantly greater final weight (22.1 g vs. 17.8 g) than shrimp in the T-HS treatment (P ≤ 0.020). The results of this study demonstrate engineering and management decisions that can have important implications for both water quality and shrimp production in intensive, minimal-exchange culture systems.     

湛江儿童公园景观设计

方案设计将以"儿童"为设计的主旨,配备与时俱进的功能和设施,丰富多彩的游乐场地,从本土特色海洋文化和传统中寻找设计灵感和元素,使得设计中更富有地域特色,帮助儿童认识和热爱家乡,从而打造极富特色并能够培养和锻炼孩子各方面能力,极具启发性、互动性、娱乐性的寓学于乐的儿童公园。     

Designing marine reserves for interacting species: Insights from theory

The primary goals of marine reserves include protecting biodiversity and ecosystem structure. Therefore, a multispecies approach to designing and monitoring reserve networks is necessary. To gain insight into how the interactions between species in marine communities may affect reserve design, we synthesize marine reserve community models and community models with habitat destruction and fragmentation, and we develop new extensions of existing models. This synthesis highlights the potential for species interactions to alter reserve design criteria; in particular, accounting for species interactions often leads to an increase in reserve size necessary to protect populations. Accounting for species interactions also indicates the need to base reserve design and monitoring on a variety of species, especially long-distance dispersers, inferior colonizers, and specialists. Finally, the new model extensions highlight how, given dispersal, source populations outside reserves as well as increases in fished populations after reserve establishment may negatively affect reserve populations of competitors or prey. Therefore, multispecies harvest dynamics outside reserves and before reserve establishment are critical to determining the appropriate reserve size, spacing, and expectations after establishment. These models highlight the importance of species interactions to reserve design and provide guidelines for how this complexity can begin to be incorporated into conservation planning.     

Testing the utility of abiotic surrogates for marine habitat mapping at scales relevant to management

Habitat mapping at the scale at which marine protected areas are designed and managed is essential for assessment of, and design for, representation. Most habitat mapping studies rely solely or in part on abiotic surrogates for patterns of biodiversity. The utility of abiotic variables in predicting biological distributions at the local scale (10 s of km) was tested in a remote video survey of macrobenthos in Moreton Bay, Australia. Habitat classifications of the same set of 41 sites based on 6 abiotic variables and abundances of 89 taxa and bioturbation indicators were compared using correlation, regression and ordination analyses. The concepts of false homogeneity (abiotically similar but biologically distinct) and false heterogeneity (abiotically distinct but biologically similar) were defined to describe types of errors associated with using abiotic surrogates to construct habitat maps, and quantified using two separate methods. Overall, the best prediction by abiotic surrogates explained less than 30% of the pattern of biological similarity. Errors of false homogeneity were between 20% and 62%, depending on the methods of estimation. Predictive capability of abiotic surrogates at the taxon level was poor, with only 6% of taxon/surrogate correlations significant. Abiotic variables did not discriminate sufficiently between different soft bottom communities to be a reliable basis for mapping. These results have implications for the widespread use of abiotic surrogates in marine habitat mapping to plan for, or assess, representation in marine protected areas. Little confidence can be placed in marine habitat classifications based solely or largely on abiotic surrogates without calibration by rigorous biological surveys at the appropriate scale. Therefore, it is questionable whether marine protected areas designed on this basis can have measurable benefits for conservation.     

Effects of habitat characteristics and sedimentation on performance of marine reserves in St. Lucia

This study examines factors affecting the rate and extent of biomass build-up among commercially important groupers, snappers, grunts, parrotfish and surgeonfish in a network of four marine reserves in southwest St. Lucia, Caribbean. Reserves constituted 35% of the total reef area originally available for fishing. Protection was instigated in 1995 after a baseline survey with annual or biennial censuses performed until 2002. Each survey consisted of 114 fifteen minute fish counts in reserves and 83 in fishing grounds, at depths of 5 m and 15 m in a 10 m diameter counting area. Estimates of number and size (cm) of target species were used to calculate fish family biomass. Data were analysed using three-way ANOVA in a before-after-control-impact pairs (BACIP) design. All families increased significantly in biomass over time at nearly all sites. Increases were greater in reserves than fishing grounds, except for grunts, and responses were strongest in parrotfish and surgeonfish. The combined biomass of families more than quadrupled in reserves and tripled in fishing grounds between 1995 and 2002. During this period coral cover declined by 46% in reserves and 35% in fishing grounds. Multiple regression showed that neither habitat characteristics nor habitat deterioration significantly affected rates of biomass build-up. The key factor was protection from fishing, which explained 44% of the variance in biomass growth. A further 28% of the variance was explained by sedimentation, a process known to stress reef invertebrates, significantly reducing the rate of biomass build-up. St. Lucia’s reserves succeeded in producing significant gains to fish stocks despite coral cover and structural complexity falling steeply over the period of the study.     

At-sea distribution of waved albatrosses and the Galápagos Marine Reserve

Albatross populations worldwide are threatened by incidental takes in longline fishery operations. The recent establishment of the Galápagos Marine Reserve (GMR) is relevant to the longline bycatch issue, as it prohibits industrial longlining in the vicinity of the major nesting site of waved albatrosses (Phoebastria irrorata). However, the legality of the fishing protections is being challenged, highlighting a need for data on use of the GMR by albatrosses. We used satellite tracking over a total of four breeding seasons to determine the distribution of waved albatrosses inside and outside the GMR, and thereby assess the degree of protection that GMR provisions offer to this species. During the incubation period, breeding adults made commuting trips from the nesting island (Isla Española) to the Peruvian upwelling zone, traveling north, east, and south after leaving the nest. During the brooding period, the distribution contracted markedly, and most satellite fixes were within the GMR. During the rearing period, breeders performed both long trips outside the GMR and short trips within. The southeastern portion of the GMR is used throughout the incubation, brooding, and early rearing periods by breeding waved albatrosses. Indirect information from non-breeding adults indicates that they are likely to use the waters of the GMR extensively.     

Impacts of lost fishing gear on coral reef sessile invertebrates in the Florida Keys National Marine Sanctuary

The Florida Keys coral reef ecosystem supports multimillion-dollar commercial and recreational fisheries. The ecological effects caused by fishing gear that is lost when cut or broken after snagging on the bottom is a growing concern to managers and scientists. Few data exist, however, to assess the impacts of lost fishing gear to benthic organisms and habitat structure. In this study, 63 offshore coral reef and hard-bottom sites were surveyed during 2001 to quantify the impacts of lost fishing gear to coral reef sessile invertebrates. Lost hook-and-line fishing gear accounted for 87% of all debris (N=298 incidences) encountered and was responsible for 84% of the 321 documented impacts to sponges and benthic cnidarians, predominantly consisting of tissue abrasion causing partial individual or colony mortality. Branching gorgonians (Octocorallia) were the most frequently affected (56%), followed by milleporid hydrocorals (19%) and sponges (13%). Factors affecting the impacts of lost fishing gear include sessile invertebrate density, the density of lost fishing gear, and gear length. While lost hook-and-line fishing gear is ubiquitous in the Florida Keys, less than 0.2% of the available milleporid hydrocorals, stony corals, and gorgonians in the habitats studied are adversely affected in terms of colony abrasions and partial mortality.