The Effect Of Spatial Scale On Food Web Structure

This was achieved by conducting freshwater sampling techniques at Flinders Lake, then analysing the samples under dissecting microscopes to identify micro invertebrates. It was hypothesised “Species richness of micro invertebrate species will be greater at the shore in comparison to one meter far from the shore in Flinders

Although it supports a number of different organisms, Nudgee Beach lacks many of the fundamentals that make up a healthy and successful ecosystem. The first indicator of this is from the lack of birds present in the area. Although it has been noted for terrestrial bird species – such as kingfishers, pelicans, ibis, egrets, jabiru, stilts and heron – and wading bird species – such as golden plovers, curlews, tattlers and godwits – to have been spotted at Nudgee Beach and surrounding areas in the past; after a day’s worth of extensive observation and research, it was found that the birds observed were limited to magpie, ibis, great knot and eastern curlew species. To intensify this factor, at the time by which this lack of species was recorded, Nudgee Beach was expected to have started seeing tens of thousands of birds arrive for the migratory season [21]. This blatant lack of bird species diversity and quantity may have been due to the lack of small organisms within the ecosystem. The restricted number of small organisms at Nudgee Beach is detrimental to the entire ecosystem as these organisms make up the bottom levels of the food web and provide higher-level organisms with adequate amounts of food to consume. The smaller organisms expected to be observed – including; crustacean, shell, mollusc, lizard, frog, fish, worm, arachnid and insect species – was limited to the infrequent observation of crustacean, shell,

Questions and charts are from Geoscience Laboratory, 5th ed. (p. 117-130), by T. Freeman, 2009, New York, NY: John Wiley & Sons. Reprinted with permission.

Questions and charts are from Geoscience Laboratory, 5th ed. (p. 133-150), by T. Freeman, 2009, New York, NY: John Wiley & Sons. Reprinted with permission.

The Ontario Benthos Biomonitoring Network was created to assess the quality of aquatic environments and ecosystems using benthos organisms as biomarkers (Ontario Ministry of the Environment, 2007). Exclusively used in Ontario, this biomonitoring program assesses ecological function and condition of streams, rivers, lakes, and wetlands across the province (The Dorset Environmental Science Centre, 2017). The OBBN protocol is ideal for assessing water quality because of the use of aquatic macroinvertebrates (Borisko, et al. 2007). Since macroinvertebrates are easy and inexpensive to collect, determining water quality can be conducted continuously over the course of the year, across many locations (Borisko, et al. 2007; Ontario Ministry of the

Questions and charts are from Geoscience Laboratory, 5th ed. (p. 155–167), by T. Freeman, 2009, New York, NY: John Wiley & Sons. Reprinted with permission.

Heath Creek, located in Northfield, MN, was sampled at four locations: A, B, C and D in which each location was measured for depth and sampled for macroinvertebrates. Locations A, B, C, and D were respectively labeled according to the downward flow of Heath Creek into Cannon River, with Location A being farthest away from the end and Location D being near the merge of Heath Creek and the Cannon River. In every location, an area of 21 meters was measured and divided into three sections of 7 meters. In each section, the depth for the deepest and most shallow sites were measured, followed by a collection of two separate representative samples of the deepest and most shallow sites. Sampling was performed through a minute of D-net jabbing and another

Trophic cascades are powerful forces that have a pronounced effect on ecosystems. They occur when predation causes shifts in prey dynamics that indirectly lead to enhanced survival in the next lowest trophic level. Walleye fishing bans at Lac la Biche coinciding with a restocking effort have led to a large recovery of walleye populations. The increase in populations of a high trophic level predator should cause shifts in a lower trophic level species (yellow perch) prey preferences from fish towards invertebrate prey. 576 yellow perch stomach collected from 2009 - 2013 by Alberta Environment and Sustainable Resource Development were sent to MacEwan University for processing/analysis. Yellow perch stomachs will be measured (dry weight, empty weight), and prey items will be removed identified and weighed. Sampling procedure differs depending on the type of prey item removed from the stomach (fish, macro and micro invertebrates). Length and weight measurements will be taken for fish and macro invertebrates; whereas, micro invertebrates will be sub sampled until 50-100 individuals can be identified. Data will be analyzed using multi

It is especially important to study and understand the characteristics of these oceanographic profiles, as it is this primary production that will have large impacts on species diversity and marine food web assemblages.

Foveaux Strait contains unique biogenic habitats that supports an important commercial oyster fishery. Regular surveys recorded stock abundance of target oyster species and bycatch, however little is known about the algae community within this region (Michael et al., 2013). Algae can be an important habitat forming organism. In particular calcifying coralline algae has been demonstrated to facilitate the settlement of many invertebrate larvae, inhibit settlement and growth of other seaweed species and enhance local biodiversity (Nelson, 2009; McCoy & Kamenos, 2015). Coralline algae can survive in conditions not typical of other fleshy algae species such as low light and high sand scouring conditions within the Strait (McCoy & Kamenos, 2015).

Cobia (Rachycentron candum) goes by many English variant common names, such as, black kingfish, black salmon, cabio, crabeater, cubby yew, kingfish, lemonfish, ling, prodigal son, runner and sergeant fish (NOAA, 2014; Bester, n.d.). The initial taxonomy of cobia was labeled as Gasterosteus canadus by Linnaeus in 1766 and then later changed to the current name Rachycentron candum (as cited in Bester, n.d.). Often the cobia is misidentified as a shark or a remora (family Echeneidae) which is the closest living relative to the cobia. Incidentally, the cobia is the only member of the family Rachycentridae. The historical range of the species is within tropical, subtropical and warm-temperate waters worldwide with the exception of

We compared linear model and generalised additive model (GAM) with a smoothing function of 0.6 using analysis of variance (with a Chi-square test). The results indicated that incorporating nonlinear effects improved the model considerably (P=0.0001), which was reflected in significantly lower AIC values of GAM (AIC=292. 9) compared to linear model (AIC=305.6). This suggests a non - linear response in S to temperature changes throughout the year, with the highest species richness at more moderate temperatures (Figure

Different statistics have been calculated revealing the extent of mixotrophs in the environment and their resulting effect on the food web. A study by Dolan and Pérez found that mixotrophs represent “on average about 30% of oligotrich numbers” in the ocean and are a “generally minor component of oligotrich communities” (Dolan and Pérez, 2000). However, recent research by Leles et al. shows that mixotrophs represent “approximately 40% of total ciliate biomass” and even influence the biological carbon pump (Leles et al., 2017). In addition, Gast et al. found that mixotrophs “can have significant impact on polar food webs” (Gast et al., 2014). These contradicting statements regarding the importance of mixotrophs in the oceanic food web show the need for further research on exactly what and how they contribute to the ecosystems they populate. Nevertheless, most scientists agree that mixotrophs do impact the oceanic biomes in some

In order to determine how changes in spatial scale affected food web structure and ecosystem processes, we sampled each site at four spatial scales within a range of varying lag, i.e. 1 m (n=1), no less than 10 m apart (n=3), no less than 10 m but no more than 100 m apart (n=6) and no less than 100 m apart, but no more than 1000 m apart (n=12), resulting in 22 samples within each site, defined by marked quadrats. By calculating the mean distance (i.e. lag in m) between the samples at each scale, we made lag a continuous variable.

The aim of this investigation is to look at the distribution of the ornate limpet, (Cellana Ornata) and the radiate limpet (Cellana Radians) on the rocky shore. We went to the rocky shore of Sirens rocks between Island Bay and Owhiro Bay, on Wellington’s South Coast. We are studying how our chosen organisms affect each other’s distribution patterns. We sampled in the low tide zone, mid tide zone, and high tide zone. The rocky shore we explored was 80 metre long, rocky terrain, bare rock platforms with rock gulley’s.