An understanding of undesirable disturbance to the balance of organisms is needed to diagnose marine eutrophication as defined by EU Directives and OSPAR. This review summarizes the findings of the ...UK Defra-funded Undesirable Disturbance Study Team, which concluded that ‘an undesirable disturbance is a perturbation of a marine ecosystem that appreciably degrades the health or threatens the sustainable human use of that ecosystem’. A methodology is proposed for detecting disturbance of temperate salt-water communities dominated by phytoplanktonic or phytobenthic primary producers. It relies on monitoring indicators of ecosystem
structure and
vigour, which are components of health. Undesirable disturbance can be diagnosed by accumulating evidence of ecohydrodynamic type-specific changes in: (i)
bulk indicators; (ii)
frequency statistics; (iii)
flux measurements; (iv)
structural indicators; and (v)
indicator species. These are exemplified by (i) chlorophyll, transparency, dissolved oxygen, and opportunistic seaweed cover; (ii) HABs frequency; (iii) primary production; (iv) benthic and planktonic ‘trophic indices’; (v) seagrasses and
Nephrops norvegicus. Ecological Quality Objectives are proposed for some of these. Linking the diagnosis to eutrophication requires correlation of changes with nutrient enrichment. The methodology, which requires the development of a
plankton community index and emphasizes the importance of primary production as an indicator of
vigour, can be harmonized with the EU Water Framework Directive and OSPAR’s
Strategy to Combat Eutrophication.
Written submissions are traditionally used in the assessment of applications for Fellowship of the Higher Education Academy, with dialogue offering an alternative approach. Quite why individuals ...elect for dialogue has received little attention. Using a mixed methods approach, data were gathered from two Universities offering dialogic and written routes in their Fellowship schemes. Most individuals elected for dialogue, although this decision varied between Fellowship categories. Reasons for the choice were highly individual. This study demonstrates that dialogic approaches are popular with staff. However, we argue the importance of choice in Fellowship assessment options and recommend this to other academic developers.
Many soft-bottom benthic invertebrates display sediment-associated patterns of dispersion. Habitat selection experiments have shown that the larvae of some species can choose to settle in favourable ...habitats, and this process could establish patterns observed in the field. However, many soft-bottom infauna, including the bivalves
Cerastoderma edule and
Macoma balthica, show postlarval relocation. Such movements could obviate patterns established at initial settlement, and active habitat selection in these postlarval stages may be responsible for adult distributions. We investigated sediment selection in postlarval stages of these bivalves on an intertidal mudflat using a field survey and experiment. Our 1225 m
2 grid survey showed a strong spatial correlation between the smallest individuals of both species, which showed no correlation with sediment characteristics. Larger size groups showed increasingly strong associations with sediment type:
C. edule with sandy sediments and
M. balthica with muddy. In our sediment choice experiment, the numbers of bivalves recruited into muddy, sandy and muddy depression (to detect small-scale hydrodynamic effects) treatments after 2 days in the field were recorded. There were no significant treatment effects in either
C. edule or
M. balthica. All bivalves were too large to be initial settlers; they were thus relocating individuals. Neither the survey nor the experiment provided any evidence that relocating individuals of these two species could choose the sediment in which they alight. The sediment-related patterns observed in adults of these species must therefore be due to other mechanisms, possibly postsettlement predation by
Carcinus maenas and/or an ability to leave less-preferred sediments in a series of migrations until the preferred habitat is found.
Social media platforms such as Twitter, Facebook and Instagram have been used to great effect to communicate the urgency required to halt and reverse tropical forest loss (Lamb et al., 2005) and the ...plight of coral reefs (Curnock et al., 2019). Apart from these important ecosystem functions, goods and services, mangrove forests are home to a huge diversity of organisms with ecologically and evolutionarily unique adaptations to life in the intertidal zone, including vivipary and salt tolerance in trees, air-breathing in crabs and amphibious behavior in fish (mudskippers); this makes mangrove forests a dynamic and fascinating evolutionary laboratory. Where the conservation of endangered ecosystems such as mangroves, mudflats, seagrass meadows, salt marshes, coral reefs, and tropical rainforests is at risk and in need of increasing public support, the continuing reference to negative perceptions may fuel under-valuation and lead to further habitat loss. Author's Note As per Frontiers style the affiliations are listed in the order that they appear in the affiliations list. ...note that the IUCN Species Survival Commission's Mangrove Specialist Group (3) is the secondary or tertiary affiliation for each of the authors.
Deforestation of mangroves is of global concern given their importance for carbon storage, biogeochemical cycling and the provision of other ecosystem services, but the links between rates of loss ...and potential drivers or risk factors are rarely evaluated. Here, we identified key drivers of mangrove loss in Kenya and compared two different approaches to predicting risk. Risk factors tested included various possible predictors of anthropogenic deforestation, related to population, suitability for land use change and accessibility. Two approaches were taken to modelling risk; a quantitative statistical approach and a qualitative categorical ranking approach. A quantitative model linking rates of loss to risk factors was constructed based on generalized least squares regression and using mangrove loss data from 1992 to 2000. Population density, soil type and proximity to roads were the most important predictors. In order to validate this model it was used to generate a map of losses of Kenyan mangroves predicted to have occurred between 2000 and 2010. The qualitative categorical model was constructed using data from the same selection of variables, with the coincidence of different risk factors in particular mangrove areas used in an additive manner to create a relative risk index which was then mapped. Quantitative predictions of loss were significantly correlated with the actual loss of mangroves between 2000 and 2010 and the categorical risk index values were also highly correlated with the quantitative predictions. Hence, in this case the relatively simple categorical modelling approach was of similar predictive value to the more complex quantitative model of mangrove deforestation. The advantages and disadvantages of each approach are discussed, and the implications for mangroves are outlined.
Student performance in and attitudes towards oral and written assessments were compared using quantitative and qualitative methods. Two separate cohorts of students were examined. The first larger ...cohort of students (n = 99) was randomly divided into 'oral' and 'written' groups, and the marks that they achieved in the same biology questions were compared. Students in the second smaller cohort (n = 29) were all examined using both written and oral questions concerning both 'scientific' and 'personal development' topics. Both cohorts showed highly significant differences in the mean marks achieved, with better performance in the oral assessment. There was no evidence of particular groups of students being disadvantaged in the oral tests. These students and also an additional cohort were asked about their attitudes to the two different assessment approaches. Although they tended to be more nervous in the face of oral assessments, many students thought oral assessments were more useful than written assessments. An important theme involved the perceived authenticity or 'professionalism' of an oral examination. This study suggests that oral assessments may be more inclusive than written ones and that they can act as powerful tools in helping students establish a 'professional identity'. PUBLICATION ABSTRACT
Anthropogenic impacts on biodiversity across a wide range of ecosystems are well documented; however the responses of ecosystems to reduced diversity are still poorly understood. We investigated the ...effects of species richness, species identity and environmental variables on aboveground biomass increment using replanted mangroves at Gazi Bay, Kenya. We planted 32 plots (36 m²) with 8 treatments: all possible combinations of the treesAvicennia marina,Bruguiera gymnorrhiza, andCeriops tagaland an unplanted control. Trees were planted in July and August 2004 and monitored annually until 2009. Growth was slow in the first 2 yr of the study, but by 2007 there was a significant treatment effect on aboveground biomass.A. marinashowed strong competitive traits, with the best growth overall and enhanced growth of individual trees when planted in mixed species plots. The highest biomass was recorded in 3-species mixes; partitioning the net effects of species mixing showed a strong species selection effect, but there was also a complementarity effect in some of the three species plots. Biomass was positively correlated with presence ofA. marinaand negatively correlated with sediment salinity. We conclude that there is variation in the stages of plant development at which species richness effects manifest themselves; in addition the effects of environmental variables have a bearing on the nature and direction of the relationship between species richness and ecosystem function.
We examined the wildlife knowledge of primary (aged 4-12) schoolchildren. In particular, we examined the effects of children's age and gender, as well as the taxonomy and origin (indigenous versus ...exotic) of wildlife, on the degree of knowledge about different species.We used illustrated 'flashcards' of mammals, birds and arthropods, drawn randomly from a species pool. Each indigenous example was paired with an exotic animal. Wildlife knowledge overall increased steadily with age, although the ability to identify species peaked at age 9 then declined slightly. Boys had significantly greater wildlife knowledge than girls, and children of both sexes identified more indigenous than exotic species. Knowledge of mammals was significantly better than that of birds and arthropods. Knowledge of some very common indigenous species, such as sparrow and earwig, was poor.We conclude that the potential for primary school wildlife education using common and easily accessible species of birds and arthropods is not fully realised, and that girls in particular lack knowledge of local species.
In the absence of well-resolved food webs that include both information on predators and parasites, body-size has been proposed as the biological mechanism underlying the assumption of a trophic ...hierarchy in the cascade model and its variants. We show that parasites consume prey larger than themselves, and therefore the logical conclusion is that the trophic hierarchy cannot be justified on the basis of body-size when food webs include parasites. Two other assumptions central to the cascade model and its variants, the link-species scaling law and the probability of predation, are not supported by the empirical data presented here. We show that linkage density is scale-dependent rather than independent, but that the relationship between linkage density and web size is far from clear. Specifically, the webs that exclude parasites examined here, overestimate the values of linkage density and connectance by more than one order of magnitude. There is little evidence for a relationship between predator generalisation (the number of prey exploited by a predator), prey vulnerability (the number of predators exploiting a prey) and trophic position within each web, when trophic position corresponds to an ordering by size. Therefore the probability of predation neither remains constant as assumed under the original cascade model, nor increases with trophic position (increasing body-size) as assumed under some of its variants. The present study however, does show some support for the notion that the cascade model's assumption of constant predation probability should be replaced by heterogeneous predation probabilities. We also examined the relationship between the morphological niche of consumers, a metric where resources falling within a defined size are always taken, and a parameter that may be closely linked to the connectance of whole food webs, but rarely examined in empirical webs. Although we could find no evidence for trends in morphological niche with trophic position, further investigation of the consequences of individual or species-level feeding constraints on the connectance of webs may repay further investigation. We contend that the organisms often most neglected in food web studies e.g. parasites and pathogens, must be included in food webs if we are able to make more realistic descriptions of the trophic structure of natural communities, and to develop mechanistic explanations for the structure of natural food webs.
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