Comparability and Transferability in Ecosystem-Assessment Techniques and Tools: An International Case Study.

As environmental degradation now reaches around the globe, ecosystem-assessment techniques and tools (EATTs) are needed in new places and at physical scales that lie outside the previous boundaries of our accumulated technical experience. To meet this need many developing and less developed countries have adapted existing EATTs from the more developed world. In this case careful evaluation is required for their suitability in a new ecological context. I refer to this issue as tool “transferability.” A related issue arises in the context of inter-regional or very large-scale assessments. Since assessments occur in specific ecoregional settings, meta-analysis of accumulating national or regional assessment datasets must be free of contextual bias inherent in statistical data gathered using different methodologies, constrained by differing geographic particularities, and reflecting the responses of locally adapted biota. This is an issue I refer to as assessment data “comparability.” My dissertation consists of six chapters treating various issues that arise when one tries to compare ecological assessment data from two very different parts of the world: in this case Michigan and South Korea. Chapter 1 introduces general background of EATT issues and case study regions. In chapters 2-5, I analyzed transferability of hydrologic modeling, biological field sampling techniques and indicator metric development. The analysis in chapter 6, used hydrologic modeling (chapters 2 and 3) and sampling method calibrations (chapters 4 and 5) to correct regional biases in both datasets. I then used residualization techniques to correct covariate biases and directly compare the response of biological communities to urban and to agricultural land use gradients. I found (1) South Korean methods were less efficient for fish sampling but more efficient macroinvertebrate sampling; (2) methodological calibration functions were required to account for these regional differences in sampling method; (3) regional ecological normalization (residualization) and rescaling proved necessary for an unbiased comparison of LU stressor-response relationships across regions. Overall, my study suggests that EATT transferability and assessment comparability are significant but under-appreciated problems in ecological assessment and that explicit correction of regional biases are necessary for comparative analysis.PHDNatural Resources and EnvironmentUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/111529/1/ecopark_1.pd

Assessing the role of environmental factors on Baltic cod recruitment, a complex adaptive system emergent property

For decades, fish recruitment has been a subject of intensive research with stock–recruitment models commonly used for recruitment prediction often only explaining a small fraction of the inter-annual recruitment variation. The use of environmental information to improve our ability to predict recruitment, could contribute considerably to fisheries management. However, the problem remains difficult because the mechanisms behind such complex relationships are often poorly understood; this in turn, makes it difficult to determine the forecast estimation robustness, leading to the failure of some relationships when new data become available. The utility of machine learning algorithms such as artificial neural networks (ANNs) for solving complex problems has been demonstrated in aquatic studies and has led many researchers to advocate ANNs as an attractive, non-linear alternative to traditional statistical methods. The goal of this study is to design a Baltic cod recruitment model (FishANN) that can account for complex ecosystem interactions. To this end, we (1) build a quantitative model representation of the conceptual understanding of the complex ecosystem interactions driving Baltic cod recruitment dynamics, and (2) apply the model to strengthen the current capability to project future changes in Baltic cod recruitment. FishANN is demonstrated to bring multiple stressors together into one model framework and estimate the relative importance of these stressors while interpreting the complex nonlinear interactions between them. Additional requirements to further improve the current study in the future are also proposed

Biomonitoring organochlorine and cholinesterase inhibiting insecticide in eastern Iowa streams

The four chapters in this thesis provide results from five separate investigations. Chapter One describes Isonychia bicolor acetylcholinesterase (AChE) activity in Northeast Iowa rivers. During 2002 and 2003 insects were collected from 10 sites during May, July and September, three sites on the Volga River were sampled weekly during May and June and one Cedar River site was sampled monthly. Also, in 2003, three sites on the Upper Iowa were sampled weekly in May and June. Sampling often sites yielded few discernable trends, however decreasing AChE activity from upstream to downstream sites was apparent on several occasions on the Volga and Upper Iowa Rivers. AChE activity decreased following a number of storm events on the Volga and Upper Iowa Rivers, possibly indicating exposure to insecticide runoff. No significant changes occurred during monthly Cedar River sampling. Chapter Two encompasses two studies. One study investigated the effects of body size on I. bicolor AChE activity. Three size classes were sampled for AChE activity during June and August, 2002 from the Cedar River in Cedar Falls. No significant differences were found among sizes in either month. Another study maintained I. bicolor under three photoperiod treatments in stream microcosms. Weekly sampling over three weeks found no significant differences among treatments. Chapter Three investigated the effects of the insecticide terbufos on I. bicolor AChE activity. Stream microcosms were dosed 0.0, 2.5, 5, 10 and 20 µg/L terbufos for 24 hours then purged with clean water. I. bicolor were sampled 24 h, 48 h and 9 d post exposure. AChE activity in I. bicolor exposed to ~ 1 Oµg/L terbufos rebounded to control activity levels in 9 d. 20µg/L terbufos for 24 h was lethal to I. bicolor within 9 d. Chapter Four investigated the benthic community composition of an urban trout stream. Periphyton samples were collected for determination of the Autotrophic Index and macroinvertebrates were analyzed for the pesticide chlordane. Macroinvertebrate communities consisted largely of Diptera and Oligochaeta, and Autotrophic Index values were high throughout the study indicating organic enrichment. No chlordane was found in macroinvertebrate samples

A novel method for mapping reefs and subtidal rocky habitats using artificial neural networks

Reefs and subtidal rocky habitats are sites of high biodiversity and productivity which harbour commercially important species of fish and invertebrates. Although the conservation management of reef associated species has been informed using species distribution models (SDM) and community based approaches, to date their use has been constrained to specific regions where the locality and spatial extent of reefs is well known. Much of the world's subtidal habitats remain either undiscovered or unmapped, including coasts of intense human use. Consequently, to facilitate a stronger understanding of species-environmental relationships there is an urgent need for a cost and time effective standard method to map reefs at fine spatial resolutions across broad geographical extents. We used bathymetric data (∼250. m resolution) to calculate the local slope and curvature of the seabed. We then constructed artificial neural networks (ANNs) to forecast the probability of reef occurrence within grid cells as a function of bathymetric and slope variables. Testing over an independent data set not used in training showed that ANNs were able to accurately predict the location of reefs for 86% of all grid cells (Kappa = 0.63) without over fitting. The ANN with greatest support, combining bathymetric values of the target grid cell with the slope of adjacent grid cells, was used to map inshore reef locations around the Southern Australian coastline (∼250. m resolution). Broadly, our results show that reefs are identifiable from coarse-scale bathymetry data of the seabed. We anticipate that our research technique will strengthen systematic conservation planning tools in many regions of the world, by enabling the identification of rocky substratum and mapping in localities that remain poorly surveyed due to logistics or monetary constraints. © 2011 Elsevier B.V.Michael J. Watts, Yuxiao Li, Bayden D. Russell, Camille Mellin, Sean D. Connell, Damien A. Fordha