Abstract Managing protected areas requires consideration of broad scale social, ecological and in some cases, political factors. Additionally, the impacts of hyperabundant species is often a concern in protected areas as increases in breeding and foraging pressures can alter habitats dramatically. The influences of hyberabundant nesting colonies of waterbird species are well documented. Many studies indicate that waterbird species can influence canopy species as especially on the shoreline of islands, where the most abundant nesting pressures occur. On Lake Erie, Phalacrocorax auritus populations have increased dramatically from a low of 87 nests in 1979 to 16,050 nests in 2007. However, most studies have failed to address the influences that mature tree death may have on the ground layer ecosystem, including increased litter depth, herbaceous species composition and abundance and seed bank composition and viability. Consequently this study sought to quantify the nesting colonies’ influence on coarse woody litter and how nest densities and litter depth influence the herbaceous layer, the seed bank composition and viability across the extent of three Lake Erie islands. My study was designed to quantify the nesting colonies’ influence on these variables across the extent of each island, rather than just the perimeters where the majority of cormorant nests and visible damage exists. I collected my data in the summer of 2008 on East Sister Island, Middle Island and West Sister Island, using plotless-point quarter method, herbaceous layer surveys (incorporating data collected by Parks Canada and Ontario Parks in 2004 and 2007), cormorant nest counts, soil seed bank cores, and litter depth measurements. To test whether there are specific impacts of cormorant nests relegated to the island perimeters versus the rest of the island, an available subset of data on East Sister Island and Middle Island were used. These were expressed as vegetation ‘damage indices’ as classified by Parks Canada and Ontario Parks staff. Kruskal-Wallis tests were used to determine if the different damage indices reveal any influence of cormorant nest density in smaller localized areas as opposed to testing the entirety of the islands. Kruskal-Wallis tests indicated that, island-wide, none of the herbaceous species abundance, diversity (total, native or exotic), seed bank composition, or seed viability has been affected significantly (P > 0.05) by either cormorant nest numbers or large-diameter litter-fall from cormorant nesting activities. However, damage indices (calculated using aerial photography) did indicate that, P .auritus nest density does influence litter depth, herbaceous species abundance and diversity in the island perimeter. Nest density has not significantly affected seed bank abundance or seed viability. My conclusion is that cormorants do not uniformly affect the islands as there is localized damage to the herbaceous layer, restricted primarily to the perimeters of the islands. However, there remains a risk to the interior herbaceous layer of the island if the effects of nesting pressures at the edges advance inward from this perimeter.

During the 1960´s and 1970´s the number of grey seals in the Baltic Sea was decreasing rapidly, mostly due to hunting and toxic substances like DDT and PCB. When hunting became less intense and toxic substances decreased in the environment the grey seal population started to increase. Today grey seals are found common in the Baltic Sea and have started to become a big treat and a problem to the fishing industry. The grey seal destroys and enters fishing traps and consumes large quantities of the fish that have been caught. The knowledge of the grey seal, like abundance and food preferences, is today limited. It is also important to define the position of the grey seal in the ecosystem in the Baltic Sea and to be able to predict changes that could occur if the population would rapidly decrease or increase. This project was therefore started in an attempt to increase the knowledge about the grey seals food preferences. The study was made in tree separate parts. Part one contained analyses of prey remains from stomachs and digestive tract from fourteen individuals put down in two geographically separate areas. The collected material from the seal digestive tract was cleaned and otoliths (hearing stones from fish), scales and back vertebra from fish eaten by the grey seal were sorted out. With the help of hard parts collected from the intestines the food preferences of the seals could be estimated. Eight different species of prey was found. The species were herring (Clupea harengus membras), sprat (Sprattus sprattus), common whitefish (Coregonus spp), perch (Perca fluviatilis), salmon (Salmo salar), trout (Salmo trutta) and roach (Rutilus rutilus). In two of the digestive tracts several individuals of the isopod Saduria entomon were found. No earlier studies describe the isopod as a food source for the grey seals in the Baltic Sea. The findings are therefore unique information. The results showed that during summer the main part of the grey seal diet in the gulf of Sundsvall and in the surrounding coastal area of Hårte was herring and sprat. No significant difference in food preferences was shown between the investigated seals from the gulf of Sundsvall and seals from the surrounding coastal area of Hårte. The second part was made to investigate if it was possible to build a floating platform that would work as a resting place for the grey seal. The surface of the platform was covered by a layer that keeps the seal scats on the platform so that it could be collected. Otoliths from herring and common whitefish were found on the floating platform. Because the platform could not be under surveillance during the whole study some uncertainties about whether the otoliths found came from grey seal or from resting cormorants or other fish eating birds. However, the otolit size is linearly related to the fish size and this relationship can be used to track the predator. Otoliths from herring taken by grey seals and otoliths found on the platform were significantly bigger than the otoliths originating from the prey of cormorants. The results indicated that the common whitefish size was too big for a full grown cormorant bird to consume. The common whitefish size showed that it probably not had been cormorants that had deposited the otoliths on the platform. The platform method was concluded promising but it needs to be modified in order to work more effective in the future. In the third part scats were collected from the area of Österåsen to increase the amount of information about the grey seals food preferences. The knowledge of the grey seals diet in the Baltic Sea is today limited and few similar study’s have earlier been made. The collected scats and otoliths in this project are therefore unique. 2008:Bi 2

<p>During the 1960´s and 1970´s the number of grey seals in the Baltic Sea was decreasing rapidly, mostly due to hunting and toxic substances like DDT and PCB. When hunting became less intense and toxic substances decreased in the environment the grey seal population started to increase. Today grey seals are found common in the Baltic Sea and have started to become a big treat and a problem to the fishing industry. The grey seal destroys and enters fishing traps and consumes large quantities of the fish that have been caught.</p><p>The knowledge of the grey seal, like abundance and food preferences, is today limited. It is also important to define the position of the grey seal in the ecosystem in the Baltic Sea and to be able to predict changes that could occur if the population would rapidly decrease or increase. This project was therefore started in an attempt to increase the knowledge about the grey seals food preferences. The study was made in tree separate parts. Part one contained analyses of prey remains from stomachs and digestive tract from fourteen individuals put down in two geographically separate areas. The collected material from the seal digestive tract was cleaned and otoliths (hearing stones from fish), scales and back vertebra from fish eaten by the grey seal were sorted out. With the help of hard parts collected from the intestines the food preferences of the seals could be estimated. Eight different species of prey was found. The species were herring (Clupea harengus membras), sprat (Sprattus sprattus), common whitefish (Coregonus spp), perch (Perca fluviatilis), salmon (Salmo salar), trout (Salmo trutta) and roach (Rutilus rutilus). In two of the digestive tracts several individuals of the isopod Saduria entomon were found. No earlier studies describe the isopod as a food source for the grey seals in the Baltic Sea. The findings are therefore unique information. The results showed that during summer the main part of the grey seal diet in the gulf of Sundsvall and in the surrounding coastal area of Hårte was herring and sprat. No significant difference in food preferences was shown between the investigated seals from the gulf of Sundsvall and seals from the surrounding coastal area of Hårte.</p><p>The second part was made to investigate if it was possible to build a floating platform that would work as a resting place for the grey seal. The surface of the platform was covered by a layer that keeps the seal scats on the platform so that it could be collected. Otoliths from herring and common whitefish were found on the floating platform. Because the platform could not be under surveillance during the whole study some uncertainties about whether the otoliths found came from grey seal or from resting cormorants or other fish eating birds. However, the otolit size is linearly related to the fish size and this relationship can be used to track the predator. Otoliths from herring taken by grey seals and otoliths found on the platform were significantly bigger than the otoliths originating from the prey of cormorants. The results indicated that the common whitefish size was too big for a full grown cormorant bird to consume. The common whitefish size showed that it probably not had been cormorants that had deposited the otoliths on the platform. The platform method was concluded promising but it needs to be modified in order to work more effective in the future.</p><p>In the third part scats were collected from the area of Österåsen to increase the amount of information about the grey seals food preferences.</p><p>The knowledge of the grey seals diet in the Baltic Sea is today limited and few similar study’s have earlier been made. The collected scats and otoliths in this project are therefore unique.</p><p>2008:Bi 2</p>

Research on the nesting of the Double-crested Cormorant (Phalacrocorax auritus auritus) was undertaken to determine the nesting ecology of the bird on Utah Lake, Utah County, and the possible effects that diking Provo Bay would have on the cormorants breeding there. In 1973, two colonies in Provo Bay were visited weekly to determine laying dates, incubation period, clutch size, and hatching dates. Another colony, located on the dike of the Geneva Steel Reservoir, was visited daily during the spring and summer of 1973. At this colony, egg-laying occurred from 13 April to 17 May. The average clutch size was 3.8, and the egg length and width averaged 60.50 mm x 39.05 mm. An average egg volume of 49.0 cc is first reported for the subspecies. The average period of incubation was 28 days, and 29.5 percent of the eggs hatched, beginning on 20 May and ending 9 June. The young weighed an average of 36 gm at hatching with a beak length of 17 mm and tarsometatarsal length of 11 mm. These increased to 1543 gm, 73 mm, and 58 mm, respectively, in 23 days. The cormorant population on Utah Lake may be severely reduced by the diking of Provo Bay.

Darbo tikslas – ištirti dotidėjomicetų (Dothideomycetes) ir sordarijomicetų (Sordariomycetes) įvairovę bei ekologines ypatybes aliuviniuose juodalksnynuose ir kormoranų pažeistame pušyne. Darbe pirmą kartą Lietuvoje detaliai ištirta aliuviniuose juodalksnynuose ir kormoranų pažeistame pušyne dotidėjomicetų ir sordarijomicetų rūšių įvairovė ir paplitimas. Sudarytas šiuose miškuose aptiktų grybų rūšių sąvadas. Išaiškintos 72 naujos Lietuvai tirtų aukšliagrybūnų rūšys ir pateikti originalūs jų morfologijos aprašymai. Pirmą kartą Lietuvoje įvertinta aplinkos veiksnių įtaka sumedėjusių bei žolinių augalų dotidėjomicetų ir sordarijomicetų įvairovei. Darbo rezultatai pagilino žinias apie šių grybų paplitimo dėsningumus Europoje saugomuose aliuviniuose miškuose, kas gali būti panaudota šių buveinių biologinės įvairovės išsaugojimui. Kormoranų pažeistame pušyne nustatyti tirtų grybų rūšinės sudėties ir paplitimo ypatumai leidžia įvertinti šių paukščių sukeliamos hipertrofikacijos poveikį pušyno mikobiotai. / The aim of the study was to investigate the diversity and ecological properties of Dothideomycetes and Sordariomycetes in the alluvial black alder forests and the pine forest affected by cormorants. For the first time in Lithuania, detailed investigations were carried out on the diversity and distribution of Dothideomycetes and Sordariomycetes in the above-mentioned forests. The checklist of the study fungi was complied. 72 Dothideomycetes and Sordariomycetes species new to Lithuania were identified and original descriptions of their morphology were provided. The influence of abiotic factors on the diversity of woody and herbaceous plants fungi was evaluated for the first time in Lithuania. The results of the study enhanced the knowledge about the distribution of Dothideomycetes and Sordariomycetes in the alluvial forests protected in Europe, which may be used to protect the biologic diversity of these habitats. The properties of the diversity and distribution of studied fungi in the pine forest affected by cormorants allow assessing the impact of the hypertrophication, caused by these birds on the pine forest mycobiota.

The aim of the study was to investigate the diversity and ecological properties of Dothideomycetes and Sordariomycetes in the alluvial black alder forests and the pine forest affected by cormorants. For the first time in Lithuania, detailed investigations were carried out on the diversity and distribution of Dothideomycetes and Sordariomycetes in the above-mentioned forests. The checklist of the study fungi was complied. 72 Dothideomycetes and Sordariomycetes species new to Lithuania were identified and original descriptions of their morphology were provided. The influence of abiotic factors on the diversity of woody and herbaceous plants fungi was evaluated for the first time in Lithuania. The results of the study enhanced the knowledge about the distribution of Dothideomycetes and Sordariomycetes in the alluvial forests protected in Europe, which may be used to protect the biologic diversity of these habitats. The properties of the diversity and distribution of studied fungi in the pine forest affected by cormorants allow assessing the impact of the hypertrophication, caused by these birds on the pine forest mycobiota. / Darbo tikslas – ištirti dotidėjomicetų (Dothideomycetes) ir sordarijomicetų (Sordariomycetes) įvairovę bei ekologines ypatybes aliuviniuose juodalksnynuose ir kormoranų pažeistame pušyne. Darbe pirmą kartą Lietuvoje detaliai ištirta aliuviniuose juodalksnynuose ir kormoranų pažeistame pušyne dotidėjomicetų ir sordarijomicetų rūšių įvairovė ir paplitimas. Sudarytas šiuose miškuose aptiktų grybų rūšių sąvadas. Išaiškintos 72 naujos Lietuvai tirtų aukšliagrybūnų rūšys ir pateikti originalūs jų morfologijos aprašymai. Pirmą kartą Lietuvoje įvertinta aplinkos veiksnių įtaka sumedėjusių bei žolinių augalų dotidėjomicetų ir sordarijomicetų įvairovei. Darbo rezultatai pagilino žinias apie šių grybų paplitimo dėsningumus Europoje saugomuose aliuviniuose miškuose, kas gali būti panaudota šių buveinių biologinės įvairovės išsaugojimui. Kormoranų pažeistame pušyne nustatyti tirtų grybų rūšinės sudėties ir paplitimo ypatumai leidžia įvertinti šių paukščių sukeliamos hipertrofikacijos poveikį pušyno mikobiotai.

This thesis is concerned with environmental conflict between local population and the protection of cormorants. In the introduction, I deal with biology, bionomics and taxonomy of cormorants. The literature retrieval is worked out in other part of the thesis. On the basis confrontation of current report made by international program COST, project MSMT Czech Republic and the evaluation of the information from the local survey the plan is suggested in terms of interdisciplinary access to the problem. I also worked out European analysis of media.