Ecological Survey Techniques: The field project

Abstract

Reduction in biodiversity due to the degradation of riverine habitats is an ongoing concern worldwide. Historically, channelization was commonplace in the USA and elsewhere, and has had pronounced detrimental effects on the biodiversity of lotic ecosystems. The objective of this project was to provide a baseline survey of the fish populations currently using a historically channelized section of Fox Creek, a second order headwater stream in Stark County Ohio. The stream will be the subject of a re-naturalization scheme in late 2015. This project will provide information both about the current state of the fish community in the stream, and inform the post-naturalization monitoring program. A combination trap and net surveying was used, fish identified to species level and life stage and gender noted when possible. Environmental data was collected and details of the current thalweg prepared.

The fish community structure was heavily dominated by one generalist running-water cyprinid, Semotitus atromaculatus, and there was low species diversity. If possible, post-restoration surveys should aim to compare aim the results with the upstream forested stretch of the creek, and to an unmodified site, where natural river features such as the pool-riffle pattern will be more apparent. Findings from such studies will contribute to a greater understanding of the effects of stream restoration on fish assemblages small streams, and will be valuable in future stream restoration efforts within the wider area.

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Abstract:

Vegetation composition, cover and invertebrate assemblages are compared on three adjacent lowland valley mires in Dorset at different stages; pre-restoration, 6-months post restoration and a reference mire in pristine condition. Sixty-seven quadrats were sampled across the three sites. Percentage cover of plant species was recorded using a grided 2mx2m quadrat. Invertebrates were sampled using dry pitfall-traps left for 24 hours and ground searches conducted within a 2-metre radius. Species richness per quadrat was greatest on the pristine site where positive bioindicator cover of 10-30% was consistent and mean Vegetation Quality Score (VQS) highest. No significant difference in Fauna Species Quality Score (FSQS) between sites were recorded and no correlation could be made between VQS and FSQS. Rewetting interventions 6-months post restoration resulted in the establishment of ruderal vegetation and positive indicator peatland species in 79% of quadrats though future temporal surveys will be valuable to record subsequent successional changes.

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Abstract

Herbivorous fish are important to the coral reef ecosystem, bridging primary producers and upper trophic consumers. Their complementary functions (browsing, grazing, scraping and excavating) can limit algae, preventing it from shading corals from photosynthesis and opening up spaces for coral recruitment. However, the debate on top-down versus bottom-up control of algae has led to disagreement on herbivorous fish protective measures and enforcement within the Indonesia government. This research aimed to explore herbivore functions and link these to patterns in benthic community composition, so to explore the contribution of herbivorous fish. Surveys were carried out at the Kaledupa region, Wakatobi Marine National Park, Indonesia. DiverOperated Stereo-Video Counting was employed to film 3 x 50m transects (at each of 3 depth zones) for four sites. Algae percentage cover was found to be low at all sites, but grazers/detritivores group were found different and higher in the heavily fished site. Grazing functions seemed obvious. However, no significant correlation was found between herbivorous fish and algae. It is recommended that surveying be included on more sites. Notably, the functional length categories showed absence of fish £ 7.5 cm (fry stage) in 4 functional groups (except farmer), this was an alarming news of losing the species, hence, Wakatobi government is recommended to enforce protection on these length categories, by restricting the mesh size, prohibiting of certain type of gears and even having fishing closed seasons (Ahamadia et al., 2013; Comeros-Raynal et al., 2012).

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Abstract

Field Fleawort (Tephroseris integrifolia subsp. integrifolia) is a yellow chalk grassland perennial that is declining across its range. In the UK, populations have been designated as vulnerable to extinction and yet very few studies have been carried out to understand the factors affecting its survival. This current study asks whether insufficient flowering and seed-set, or interruption of these processes through grazing, is contributing to Field Fleawort’s decline. A demographic study of 147 plants across two national nature reserves (Barton Hills and Knocking Hoe, Bedfordshire, UK) was carried out to monitor flowering, pappus production and signs of grazing between April and June 2024. Over half of the plants flowered at each site but differences in grazing pressure led to significant variation in the number of plants producing pappus. Analysis of grazed stems suggests that despite the presence of managed conservation livestock such as Herdwick sheep and Exmoor ponies, it is most likely rabbits that cause the primary interruption to the early phases of Field Fleawort’s reproductive cycle.

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Abstract

Vegetated coastal habitats account for an estimated 50% of carbon sequestration within the marine environment, despite comprising < 0.2% of the ocean floor. In the UK, there has been an estimated 85% decline in seagrass presence within estuaries since the 1920s. The fast growth rate of seagrasses makes them ideal candidates for the restoration or planting of meadows. The Ocean Conservation Trust planted 18,200 hessian bags containing Zostera marina seeds in Plymouth, UK. Two months post-planting, seed germination and growth success along three permanent transects was monitored via the use of SCUBA for four months (June 2021 – September 2021). Seed germination rate was lower than anticipated, and although maximum shoot length did appear to increase over the survey period, this was not statistically significant. Delays and improvisations relating to the storage of seeds brought about by the COVID-19 pandemic, and an oversight relating to the degradation of the hessian bags, hindered the project. Presented here is a preliminary report on the first phase of a novel seagrass planting project within the UK, whereby methods and materials utilised have been assessed in order to provide feedback to the OCT for the future deployment of Z. marina seeds in the area. However, the restoration and creation of seagrass meadows is a developing science, and as such, the best practice methodology to assess the status and success of planting seagrass is also yet to be determined.

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Abstract

Freshwater macrobenthos in the orders Ephemeroptera, Plecoptera and Trichoptera (‘EPT’ taxa) are known to be intolerant of poor water quality and are considered useful ‘bioindicators’ of environmental quality, being among the first macroinvertebrates to react to changes in an aquatic ecosystem. Many highland rivers in East Africa remain poorly studied, including the Mathioya, which is an important tributary of Kenya’s longest river, the Tana. This survey sampled macrobenthos from 8 sites of low and high human disturbance along a short section of the Mathioya during the rainy season. Physico-chemical parameters used in water quality assessments were also measured, with associations between these and EPT taxa tested for statistical significance. Species abundance, richness and diversity were found to be generally higher at less disturbed sites, which also held a greater proportion of pollution intolerant EPT taxa. Further observations of the feeding ecology of the macrobenthos sampled appear to support assumptions described by the river continuum concept, with implications for river management guidelines in Kenya.

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Abstract

The aim of this project is to investigate floral diversity and abundance, pollinators and associated forage interaction frequency; within 5 separate sets of field blocks under differing conservation management techniques at Kingcombe Meadows National Nature Reserve. The 5 fields are maintained by two different grassland management techniques, including cattle grazing and a hay-cut. Transects and Flower Insect Timed (FIT) counts where randomly assigned in each field, before and after the grassland management event. Pollinator, flora interactions were recorded (number and length of interactions) to look at potential preferences in forage: and to be utilised as a proxy for specialism of the taxa. The pollinator assemblages at both management stages were recorded, as were the abundance and diversity of the vegetation in blossom. Secondary data was utilised from Kingcombe Floral Group to create a complete picture of the floral resources available at Kingcombe. Data collection was largely hampered by the British ‘summer’. Limiting the amount and range of data collected. 682 pollinators were recorded across all of Kingcombe: 252 of them foraged on 25 different species of inflorescence. There where no conclusive findings found for pollinator specialism associated with grazing stage: or hay-cutting technique. There were dramatic losses in plant and pollinator biodiversity and abundance, associated with the haycut management technique.

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Abstract

Dead hedges are ancient countryside features that are still built today to utilize the logs and brash from woodland management work. This project tests the assumption generally made that dead hedges are a good habitat for small mammals. It compares the presence and activity levels at 12 study areas, six with hedges and six without, in Leyland, Lancashire (UK), using tracking tunnels and small mammal traps. It finds that at a species diversity level, presence of small mammals is the same for hedge and non-hedged sites, whilst activity levels are higher at non-hedged sites. The results suggest that small mammal activity is driven by a variety of factors including microhabitat structure, small mammal adaptations and the interaction of rats and mice more than by the presence or absence of dead hedges.

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Abstract

Port’s Island supports the only known wild population of the endemic Bermudian land snail Poecilozonites bermudensis. Observations of zoo-reared P.bermudensis released elsewhere suggest an affinity for Bermuda Palmettos and limestone (Ovaska, 2017). These microhabitat associations are investigated in the wild population, along with a suspected aversion to invasive Casuarina trees and sea coasts. Between May 2nd and June 14th 2018, 738 live P.bermudensis were found at 90 sites across Port’s Island from the shoreline to 22m elevation. There is no correlation between the number of live snails at a site and either the number of plant species present, elevation above sea level, or distance from the shoreline. P.bermudensis is significantly less abundant at Casuarina-dominated sites, while the presence of palms does not affect snail abundance. Significantly more snails are found around limestone outcrops or rock piles in the woodland, indicating future re-introductions and searches for additional wild populations should focus on rocky features where Casuarina is absent. As there is no strong association with plant communities, a range of re-introduction locations can be considered.

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Abstract

Urbanisation has been attributed to the decline in many UK native species, due to the deleterious effects it has on the environment, for example fragmentation and habitat loss. Urbanisation is the formation of towns and cities where populations move from rural areas to create urban areas. One species that may be affected by urbanisation is the butterfly (Rhopalocera), which has drastically reduced in numbers over the years. Butterflies are also seen as indicator species, where they can define environmental characteristics and be used to monitor trends in habitats. This study looked into the effect the proximity of a reserve to an urban area had on the abundance and richness of the butterfly assemblages. This was to see whether there were differences between reserves in rural areas and urban areas. In general, rural reserves showed a higher abundance and also had more species observed than their urban counterparts. A statistical significant difference was found between the two reserve categories (rural/urban) for both their abundance and richness. To improve the diversity of butterfly assemblages on urban reserves re-vegetation of urban spaces is recommended as well as protecting and monitoring such areas.

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Abstract

Urban parks seem to play important role in preserving the bird species' diversity and abundance. This study was conducted to identify bird species in four conservation parks: Jabi Lake Park, Millenium Park, Central Park and National Children Park n Zoo in Abuja from April - June 2023. A total of 312 individuals from 81 species were identified from the four parks. Each park recorded an average of 40- 54 species, National Children's Park recorded the highest species richness while Central Park had the least species recorded. Jabi Park recorded the highest count in the wetland habitat while Millenium Park recorded the highest number of bird populations in the woodland habitat. Kruks Wallis test conducted showed no difference in bird abundance in each habitat across the survey locations while Correlation analysis to test the hypothesis that tree density has an effect on the bird species richness also showed no correlation. The study identified a potential connection between plant/tree species and specific bird populations. The dominant species commonly recorded in the parks include Cypsiurus parvus (African Palm swift), Streptopelia senegalensis (Laughing Dove), Spermestes cucullata (Bronze mannikin), Ploceus cucullatus (Village Weaver), Pycnonotus barbatus (Common Bulbul). The study revealed the dominance of generalist species over water and forest specialists’ birds thus suggesting that urbanisation and human interference in these urban parks do not support the specialist birds. It is therefore recommended that future continuous monitoring be undertaken in these parks to monitor the trend and identify potential needs of these bird species which will therefore contribute towards strategies for biodiversity conservation.

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Abstract

The Axe Estuary, East Devon, contains important estuarine habitats utilised by waterbirds. Seaton town alongside the estuary is being regenerated, which could increase recreational activities resulting in higher waterbird disturbance. The study investigated the temporal and spatial effects of human disturbance on waterbirds across three stratified habitat plots (250m2 ); from Seaton harbour (Plot A), Axmouth (Plot B) and Colyford (Plot C) in the north. 96 surveys were conducted over the autumn/winter of 2017/2018. Disturbance rates (combined 1.9 per hour, high tide, falling tide) of waterbirds decreased significantly over a south to north gradient. Disturbance events changed the abundance and distribution of birds, as disturbance levels increased there were highly significant negative correlations with reduced number of waterbirds. Walking activities on intertidal habitats and loose dogs significantly reduced the numbers of birds on Plot A and B, compared to significantly higher numbers of waterbirds on Plot C. Canoes and loose dogs also increased the probability of major flights in waterbirds on Plot A and B, comparable to the Exe Estuary study. The construction of Seaton Quay will probably increase the levels of disturbance on Plot A and push more birds north, possibly leading to 250m2 of intertidal habitat being further underutilised.

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Abstract

Impervious sealing of soil surfaces in urban environments has an inhibiting effect on plant life, leading to reduced urban biodiversity. Pioneer species often establish on broken surfaces such as the cobbled mews of central London. This study uses a citizen science methodology to compare the biodiversity and percentage cover of vascular plants in ten pairs of mews, in which one is cobbled and the other tarmacked. To do so, three parallel transect lines were laid along the full length of each mews and sampled with quadrats every 20m. The influence of distance from the entrance and the edge of the mews is also explored. Both percentage cover and biodiversity are significantly higher in cobbled mews, but there is no significant impact of the location within a mews on cover. Management recommendations to maintain and conserve cobbled mews are suggested.

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Abstract

Social spiders are some of the most studied arachnids in the world, yet there are still many gaps in the research that need to be addressed that can contribute to greater scientific understanding of organisms selection and use of habitats. Host plant use by the social spiders Stegodyphus spp. was examined in a private nature reserve in Limpopo, South Africa to determine if the broad assumption that they utilise “thorny acacia” is supported by analysing nest occurrence against plant characteristics (species, height and presence or absence of thorns). Nests were abundant on Vachellia spp. Ziziphus mucronata and Senegalia nigrescens and found on larger species often facing in a westerly or northernly direction. The results suggest that structural integrity, presence of thorns and directional facing are important factors for microhabitat selection and may potentially provide benefits from predation and climatic factors

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Abstract

This study evaluates habitat suitability within the Omayed Protected Area (PA) in Egypt for the reintroduction of the critically endangered Egyptian Tortoise (Testudo kleinmanni). Geographically Weighted Regression (GWR) models and field surveys assessed key habitat parameters: Species Richness (SR), Food Plant Cover (FPC), and Proportion Bare Earth (PBE). The GWR analysis identified two potential release sites based on higher habitat suitability scores. Further analysis and contextualization, considering factors such as release site size, food plant diversity, and disturbance levels, determined Site B as the most suitable location.

A soft-release strategy is recommended to reduce predation risks and allow tortoises to acclimate, with additional measures proposed to manage human activities and grazing pressures within the PA. The study underscores the importance of habitat restoration and effective management practices to ensure the long-term success of the reintroduction program for T. kleinmanni.

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Abstract

The objective of this study was to investigate the effect of field margin placement on invertebrate abundance and diversity and the concomitant effect on two known arable predator groups, Carabidae and Araneae. Data was collected in June 2017 from pitfall traps (n=72) across 24 field sites, based on six farms in Pembrokeshire. Fields with margins located next to improved habitat were compared with those adjacent to unimproved land.

Results found no significant difference in invertebrate abundance between treatments, but a significant difference in diversity; with higher diversity at unimproved sites. The effect of location was significant for Carabid abundance and diversity; with higher numbers in crop samples. No significant effects were found when assessing spider abundance or diversity. Findings showed diverse responses between the groups in relation to foliage height and bare ground coverage.

Recommendations from the results include further study to incorporate a wider range of habitat assessments to enable further insight into the effects of field margin position within a small scale heterogeneous farmland landscape.

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