Incorporating surrogate species and seascape connectivity to improve marine conservation outcomes

Conservation focuses on maintaining biodiversity and ecosystem functioning, but gaps in our knowledge of species biology and ecological processes often impede progress. For this reason, focal species and habitats are used as surrogates for multispecies conservation, but species-based approaches are not widely adopted in marine ecosystems. Reserves in the Solomon Islands were designed on the basis of local ecological knowledge to conserve bumphead parrotfish (Bolbometopon muricatum) and to protect food security and ecosystem functioning. Bumphead parrotfish are an iconic threatened species and may be a useful surrogate for multispecies conservation. They move across tropical seascapes throughout their life history, in a pattern of habitat use that is shared with many other species. We examined their value as a conservation surrogate and assessed the importance of seascape connectivity (i.e., the physical connectedness of patches in the seascape) among reefs, mangroves, and seagrass to marine reserve performance. Reserves were designed for bumphead parrotfish, but also enhanced the abundance of other species. Integration of local ecological knowledge and seascape connectivity enhanced the abundance of 17 other harvested fish species in local reserves. This result has important implications for ecosystem functioning and local villagers because many of these species perform important ecological processes and provide the foundation for extensive subsistence fisheries. Our findings suggest greater success in maintaining and restoring marine ecosystems may be achieved when they are managed to conserve surrogate species and preserve functional seascape connections

Gelatinous Zooplankton Biomass In the Global Oceans: Geographic Variation and Environmental Drivers

Aim Scientific debate regarding the future trends, and subsequent ecological, biogeochemical and societal impacts, of gelatinous zooplankton (GZ) in a changing ocean is hampered by lack of a global baseline and an understanding of the causes of biogeographic patterns. We address this by using a new global database of GZ records to test hypotheses relating to environmental drivers of biogeographic variation in the multidecadal baseline of epipelagic GZ biomass in the world\u27s oceans. Location Global oceans. Methods Over 476,000 global GZ data and metadata items were assembled from a variety of published and unpublished sources. From this, a total of 91,765 quantitative abundance data items from 1934 to 2011 were converted to carbon biomass using published biometric equations and species-specific average sizes. Total GZ, Cnidaria, Ctenophora and Chordata (Thaliacea) biomass was mapped into 5° grid cells and environmental drivers of geographic variation were tested using spatial linear models. Results We present JeDI (the Jellyfish Database Initiative), a publically accessible database available at http://jedi.nceas.ucsb.edu. We show that: (1) GZ are present throughout the world\u27s oceans; (2) the global geometric mean and standard deviation of total gelatinous biomass is 0.53 ± 16.16 mg C m−3, corresponding to a global biomass of 38.3 Tg C in the mixed layer of the ocean; (3) biomass of all gelatinous phyla is greatest in the subtropical and boreal Northern Hemisphere; and (4) within the North Atlantic, dissolved oxygen, apparent oxygen utilization and sea surface temperature are the principal drivers of biomass distribution. Main conclusions JeDI is a unique global dataset of GZ taxa which will provide a benchmark against which future observations can be compared and shifting baselines assessed. The presence of GZ throughout the world\u27s oceans and across the complete global spectrum of environmental variables indicates that evolution has delivered a range of species able to adapt to all available ecological niches

Questioning the rise of gelatinous zooplankton in the World's oceans

During the past several decades, high numbers of gelatinous zooplankton species have been reported in many estuarine and coastal ecosystems. Coupled with media-driven public perception, a paradigm has evolved in which the global ocean ecosystems are thought to be heading toward being dominated by “nuisance” jellyfish. We question this current paradigm by presenting a broad overview of gelatinous zooplankton in a historicalcontext to develop the hypothesis that population changes reflect the human-mediated alteration of global ocean ecosystems. To this end, we synthesize information related to the evolutionary context of contemporary gelatinous zooplankton blooms, the human frame of reference forchanges in gelatinous zooplankton populations, and whether sufficient data are available to have established the paradigm. We conclude that the current paradigm in which it is believed that there has been a global increase in gelatinous zooplankton is unsubstantiated, and we develop a strategy for addressing the critical questions about long-term, human-related changes in the sea as they relate to gelatinous zooplankton blooms

Differences in Efficacy and Safety of Pharmaceutical Treatments between Men and Women: An Umbrella Review

Being male or female is an important determinant of risks for certain diseases, patterns of illness and life expectancy. Although differences in risks for and prognoses of several diseases have been well documented, sex-based differences in responses to pharmaceutical treatments and accompanying risks of adverse events are less clear. The objective of this umbrella review was to determine whether clinically relevant differences in efficacy and safety of commonly prescribed medications exist between men and women. We retrieved all available systematic reviews of the Oregon Drug Effectiveness Review Project published before January 2010. Two persons independently reviewed each report to identify relevant studies. We dually abstracted data from the original publications into standardized forms. We synthesized the available evidence for each drug class and rated its quality applying the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach. Findings, based on 59 studies and data of more than 250,000 patients suggested that for the majority of drugs no substantial differences in efficacy and safety exist between men and women. Some clinically important exceptions, however, were apparent: women experienced substantially lower response rates with newer antiemetics than men (45% vs. 58%; relative risk 1.49, 95% confidence interval 1.35–1.64); men had higher rates of sexual dysfunction than women while on paroxetine for major depressive disorder; women discontinued lovastatin more frequently than men because of adverse events. Overall, for the majority of drugs sex does not appear to be a factor that has to be taken into consideration when choosing a drug treatment. The available body of evidence, however, was limited in quality and quantity, confining the range and certainty of our conclusions

Temporal variation in the virgin biomass of the edible jellyfish, Catostylus mosaicus (Scyphozoa, Rhizostomeae)

Temporal variation in the virgin biomass and abundance of a single stock of the edible jellyfish, Catostylus mosaicus\ud (Scyphozoa, Rhizostomeae) was estimated at Lake Illawarra, a coastal lagoon in New South Wales, Australia. Density and\ud biomass were estimated three times within 3 weeks during three survey periods: April 1997, October 1997 and May 1998.\ud Density and biomass were estimated for two size classes: all medusae easily counted from a moving boat (i.e. medusae\ud ≥50mm bell diameter (BD)) and those considered to be vulnerable to the fishery (≥200mm BD). Densities of medusae\ud ≥50mm BD varied greatly between survey periods and between days within survey periods. Densities of medusae ≥200mm\ud BD were similar between survey periods but varied within survey periods. The virgin biomass of medusae≥50mmBD ranged\ud between 1831 t during April 1997 and 18,526 t during May 1998. The biomass of medusae that was vulnerable to the fishery\ud varied between 207 t in May 1998 and 2865 t in April 1997

Recruitment and growth of medusae of the schyphozoan jellyfish, Catostylus mosaicus

The timing of recruitment and growth of medusae of the commercially harvested jellyfish, Catostylus mosaicus (Scyphozoa), was examined over a period of 8 years at Botany Bay and 2.5 years at Lake Illawarra in New South Wales, Australia. Recruitment events occurred sporadically during December and between March and July at Botany Bay and between February and July at Lake Illawarra. Recruitment did not occur during late winter or spring at either location, although small numbers of recruit medusae could potentially occur during any time of year. Despite anecdotal observations that recruitment sometimes occurred after periods of heavy rain, we found no correlation between the timing of recruitment and rainfall in Botany Bay over a period of 8 years. Cohort analyses indicated growth of small medusae was very rapid (max. 4.81 mm day–1), with growth rates decreasing as medusae grew larger. Medusae appeared to grow faster at Botany Bay than Lake Illawarra. A conservative estimate indicated medusae of C. mosaicus can live for up to 13 months

Claims that anthropogenic stressor facilitate jellyfish blooms have been amplified beyond the available evidence: a systematic review: anthropogenic causes of jellyfish blooms

The perception that anthropogenic stressors cause jellyfish blooms is widespread within the scientific literature and media but robust evidence in support of these claims appears scarce. We used a citation analysis of papers published on “jellyfish blooms” to assess the extent to which such claims are made and the robustness of the evidence cited to support claims. Our search of the Web of Science returned 365 papers on “jellyfish blooms.” Each paper was searched for statements linking jellyfish blooms to specific anthropogenic stressors. For each statement we recorded the affirmation afforded to the claim, identified the stressors purported to cause blooms, the sources cited to support the statement, the type of study cited and the species studied in the cited source. Almost half the papers contained statements claiming that blooms were facilitated by anthropogenic stressors but most (70%) afforded a low degree of affirmation to the claim. We identified three major limitations in the evidence cited to support claims: (1) it was dominated by studies of two wide-spread and highly invasive taxa (Aurelia aurita and Mnemiopsis leidyi) that may not represent the responses of jellyfishes more generally; (2) the empirical evidence cited was dominated by correlative studies which, whilst useful for generating hypotheses, cannot attribute causation; and (3) the reviews most commonly-cited as evidence mostly cited circumstantial evidence and other reviews and provided conceptual models of how stressors could influence blooms, rather than robust evidence. We conclude that, although anthropogenic stressors could enhance jellyfish blooms, robust evidence is limited. Claims that strongly affirm anthropogenic stressors as causes of jellyfish blooms appear to be amplifying the evidence beyond that available. As a community we need to qualify the statements we make about jellyfish to strike a better balance between perpetuating perception and accurately portraying the state of knowledge

Shorter, warmer winters may inhibit production of ephyrae in a population of the moon jellyfish Aurelia aurita

Scyphozoan jellyfish blooms display high interannual variability in terms of timing of appearance and size of the bloom. To understand the causes of this variability, the conditions experienced by the polyps prior to the production of ephyrae in the spring were examined. Polyps reared from planula larvae of Aurelia aurita medusae collected from southern England (50°49′58.8; − 1°05′36.9) were incubated under orthogonal combinations of temperature (4, 7, 10 °C) and duration (2, 4, 6, 8 weeks), representing the range of winter conditions in that region, before experiencing an increase to 13 °C. Timing and success of strobilation were recorded. No significant production of ephyrae was observed in any of the 2- and 4-week incubations, or in any 10 °C incubation. Time to first ephyra release decreased with longer winter incubations, and more ephyrae were produced following longer and colder winter simulations. This experiment indicates that A. aurita requires a minimum period of cooler temperatures to strobilate, and contradicts claims that jellyfish populations will be more prevalent in warming oceans, specifically in the context of warmer winter conditions. Such investigations on population-specific ontogeny highlights the need to examine each life stage separately as well as in the context of its environment

Jellyfish modify the response of planktonic assemblages to nutrient pulses

The short-term effects of pulses of nutrients and jellyfish Catostylus mosaicus on planktonic assemblages were investigated in field-based experiments using 3 m3 mesocosms. Experiments ran for 5 d and were repeated in autumn and spring at Lake Illawarra, a coastal lagoon in New South Wales, Australia. Experiments consisted of 2 orthogonal treatments, addition/non-addition of nutrients and presence/absence of jellyfish, and were designed to determine how bottom-up (i.e. addition of nutrients) and top-down (i.e. predation by jellyfish) processes influence planktonic assemblages, both independently and in combination. During both experiments, nutrients stimulated primary production and caused changes in phytoplankton assemblages. Nutrients also stimulated production of large tintinnids, suggesting that bottom-up processes may influence 2 trophic levels. Mesozooplankton were consistently depleted in mesocosms containing jellyfish. Jellyfish also caused changes in microzooplankton assemblages, indicating that top-down processes also cascade to at least 2 trophic levels. In mesocosms to which both nutrients and jellyfish were added during spring, concentrations of the red-tide forming, heterotrophic dinoflagellate Noctiluca scintillans were 20 times greater than in mesocosms to which nutrients were added alone. We hypothesize that addition of nutrients stimulated production of centric diatoms, the main prey of N. scintillans, but that a bloom of N. scintillans only formed when jellyfish were also present because jellyfish grazed on populations of herbivorous mesozooplankton (particularly the calanoid copepod Gladioferens), which generally out-competed N. scintillans for diatom prey. These data provide the first empirical evidence linking jellyfish to the formation of red tides

The ecology of scyphozoan jellyfish in Lake Illawarra

The scypbozoan jellyfish of Lake Illawarra are well known to most people who use Lake Illawarra for research, commercial fishing or recreation. Here we review the biology and ecology of the two most well-studied species, Catostylus mosaieus and Phyllorhiza punetata, and present preliminary results of studies that investigated their role in the trophic and nutrient dynamics of coastal lagoons. Specifically we show that C. mosaicus is a voracious\ud predator of zooplankton and that the presence of medusae may promote production of phytoplankton either via\ud excretion of inorganic nutrients or because grazing by C. mosaicus on zooplankton, in turn, reduces grazing by zooplankton on phytoplankton. Comparisons of rates of excretion by C. mosaicus and P. punctata show that\ud C. mosaicus excretes substantial amounts of NH3 which, during times of their peak biomass, may account for\ud 8% of the NH3 required by phytoplankton. In contrast P. punctata exhibits no net excretion of NH3, probably because its excretory products are predominantly translocated to symbiotic zooxanthellae within its tissues. Hence these species have contrasting roles in nutrient regeneration. Current gaps in our knowledge of the ecology of these\ud species are identified