Harbour seals (Phoca vitulina) around an operational tidal turbine in Strangford Narrows : no barrier effect but small changes in transit behaviour

Funding: NERC Marine Renewable Energy Knowledge Exchange Programme (Contract 4060038637) and NERC grant SMRU1001.1. Data were obtained from 32 electronic tags that were glued to the fur of harbour seals (Phoca vitulina) in and around Strangford Lough, Northern Ireland, during the environmental monitoring of the SeaGen tidal turbine. 2. This study provides the first detailed information on the behaviour of marine mammals close to a commercial-scale tidal energy device. The turbine did not prevent transit of the animals through the channel and therefore did not result in a ‘barrier’ effect. 3. However, the animals' behaviour did change when the turbine was operating, demonstrating the importance of allowing for behavioural responses when estimating collision risks associated with tidal turbines. 4. Tagged animals passed the location of the device more frequently during slack water than when the current was running. In 2010 the frequency of transits by tagged seals reduced by 20% (95% CI: 10–50%) when the turbine was on, relative to when it was off. This effect was stronger when considering daylight hours only with a reduction of transit rate of 57% (95% CI: 25–64%). Seals tagged during the operational period transited approximately 250 m either side of the turbine suggesting some degree of local avoidance compared with the pre-installation results. 5. The results presented here have implications for monitoring and managing the potential interactions between tidal turbines and marine wildlife. Principally that the design of telemetry studies for measuring change in response to developments should seek to understand and take into account variability in seal behaviour. 6. This study only looked at the effects of a single turbine rather than an array, and mitigation limited the ability to determine close range interactions. However, the study indicates that the effect of the turbine on Strangford Lough harbour seals was minor and that collision risk was reduced by the behaviour of the seals.Publisher PDFPeer reviewe

Fine-scale harbour seal usage for informed marine spatial planning

The work was funded through Scottish Government MSQ0174 contract CR/2014/11; CREEM, University of St Andrews; the National Capability fund from the Natural Environment Research Council to the Sea Mammal Research Unit (grant no. SMRU1001); and MASTS pooling initiative, which is funded by the Scottish Funding Council (grant reference HR09011).High-resolution species distribution maps are required for marine spatial planning, consenting, and licensing to assess interactions between anthropogenic activities and ecosystems. This approach can inform conservation measures for protected species and facilitate commercial developments needed for economic growth. A case study centred on Orkney, UK, is an area where concern for a declining harbour seal population has led to constraints being placed on tidal energy generation developments. Telemetry data from 54 animals tagged between 2003 and 2015 were combined with terrestrial counts from 2008 to 2015 to produce density estimation maps. Predictive habitat models using GAM-GEEs provided robust predictions in areas where telemetry data were absent, and were combined with density estimation maps. Harbour seal usage maps with confidence intervals were produced around Orkney and the North coast of Scotland. The selected habitat model showed that distance from haul out, proportion of sand in seabed sediment, and peak flow of tidal current were important predictors of space-use. Fine-scale usage maps can be used in consenting and licensing of anthropogenic developments to determine local abundance. When quantifying anthropogenic impacts through changes to species distributions, usage maps could be spatially explicitly linked to individual-based models to inform predicted movement and behaviour.Publisher PDFPeer reviewe

Harbour porpoises exhibit localized evasion of a tidal turbine

Funding: Scottish Government (Grant Number(s): Marine Mammal Scientific Support Program MMSS/002/); Natural Environment Research Council (Grant Number(s): NE/R014639/1, NE/R015007/1).1. Tidal energy generators have the potential to injure or kill marine animals, including small cetaceans, through collisions with moving turbine parts. Information on the fine scale behaviour of animals close to operational turbines is required to inform regulators of the likely impact of these new technologies. 2. Harbour porpoise movements were monitored in three dimensions around a tidal turbine for 451 days between October 2017 and April 2019 with a 12-channel hydrophone array. 3. Echolocation clicks from 344 porpoise events were localized close to the turbine. The data show that porpoises effectively avoid the turbine rotors, with only a single animal clearly passing through the rotor swept area while the rotors were stationary, and none passing through while rotating. 4. The results indicate that the risk of collisions between the tidal turbine and porpoises is low; this has important implications for the potential effects and the sustainable development of the tidal energy industry.Publisher PDFPeer reviewe

Automated detection and tracking of marine mammals in the vicinity of tidal turbines using multibeam sonar

Funding: The monitoring platform was developed with funds from the Natural Environment Research Council (Grant Nos. NE/R015007/1 and NE/R014639/1). Software development and data analysis was funded by the Scottish Government as part of the Marine Mammal Scientific Support Program (Grant No. MMSS/002/15). Umbilical cables to the turbine infrastructure were funded and developed by SIMEC Atlantis.Understanding how marine animals behave around tidal turbines is essential if we are to quantify how individuals and populations may be affected by the installation of these devices in the coming decades. Our particular interest is in collision risk, and how this may be affected by the fine-scale behaviour of seals and small cetacean species around devices. We report on a study in which multibeam sonar data were collected close to an operational tidal turbine in Scotland continuously over a twelve-month period. The sonars provide high-resolution (a few cm) data over a 120° angle out to a range of 55 m at a rate of 10 frames per second. We describe a system which uses automatic computer algorithms to detect potential targets of interest, verified by human analysts using a sophisticated computer user interface to confirm detections and assign target species. To date, we have identified 359 tracks of marine mammals in the data, as well as several thousand tracks from fish and diving birds. These are currently being parameterised to study how these species react to the moving turbine rotors, and the data are now being used to explore the development of improved automated detection and classification algorithms.Publisher PDFPeer reviewe

Automated detection and tracking of marine mammals : a novel sonar tool for monitoring effects of marine industry

Funding: The work was funded under the Scottish Government Demonstration Strategy (Project no. USA/010/14)and as part of the Department of Energy and Climate Change’s Offshore Energy Strategic Environmental Assessment programme, with additional resources from the Natural Environment Research Council (grant numbers: NE/R014639/1 and SMRU1001).1. Many marine industries may pose acute risks to marine wildlife. For example, tidal turbines have the potential to injure or kill marine mammals through collisions with turbine blades. However, the quantification of collision risk is currently limited by a lack of suitable technologies to collect long‐term data on marine mammal behaviour around tidal turbines. 2. Sonar provides a potential means of tracking marine mammals around tidal turbines. However, its effectiveness for long‐term data collection is hindered by the large data volumes and the need for manual validation of detections. Therefore, the aim here was to develop and test automated classification algorithms for marine mammals in sonar data. 3. Data on the movements of harbour seals were collected in a tidally energetic environment using a high‐frequency multibeam sonar on a custom designed seabed‐mounted platform. The study area was monitored by observers to provide visual validation of seals and other targets detected by the sonar. 4. Sixty‐five confirmed seals and 96 other targets were detected by the sonar. Movement and shape parameters associated with each target were extracted and used to develop a series of classification algorithms. Kernel support vector machines were used to classify targets (seal vs. nonseal) and cross‐validation analyses were carried out to quantify classifier efficiency. 5. The best‐fit kernel support vector machine correctly classified all the confirmed seals but misclassified a small percentage of non‐seal targets (~8%) as seals. Shape and non‐spectral movement parameters were considered to be the most important in achieving successful classification. 6. Results indicate that sonar is an effective method for detecting and tracking seals in tidal environments, and the automated classification approach developed here provides a key tool that could be applied to collecting long‐term behavioural data around anthropogenic activities such as tidal turbines.PostprintPeer reviewe

Metabolic rates of captive grey seals during voluntary diving

The energetic cost of diving in marine mammals is a difficult value to derive given the problems of assessing metabolic rate for an animal at sea. Nevertheless, it is fundamental to our understanding of the foraging strategies of air-breathers exploiting underwater food sources. We measured the metabolic rates of eight captive grey seals, voluntarily diving in a quasi-natural setting. Oxygen consumption during post-dive surface periods was measured using open-flow respirometry, and dive behaviour of the seals was recorded using time depth recorders (TDRs). Mean diving metabolic rate (DMR) for both adults and juveniles was 1.7 times the predicted standard metabolic rate of terrestrial animals of equal size. For all animals, DMR was lower than the rate of metabolism measured whilst they were resting at the water's surface. On a dive-by-dive basis, DMR decreased with dive duration but increased with mean swim speed. Regressing the maximum 5% of DMRs against dive duration resulted in a significant negative relationship that was not significantly different from the relationship between the calculated maximum rate of aerobic metabolism and dive duration, suggesting that these seals were diving within, and up to, their aerobic limits. We developed a model that allows the prediction of DMR from information on dive behaviour of the type routinely collected in telemetry studies of wild seals. The model accurately predicts DMR using behavioural data from periods of diving with known metabolism data. This model can be used to predict the at-sea metabolic rate of wild grey seals, an important input into ecosystem models.</p

Tila matkalla kohti 2020-lukua : Kannattavuutta, monialaisuutta, työhyvinvointia

Maataloudessa on meneillään voimakas rakennemuutos: pienet tilat ovat lopettaneet, jatkavat tilat laajentavat, osa erikoistuu ja osa monialaistaa tuotantoaan. Opinnäytetyön tavoitteena oli tutkia kohdetilan strategisia suunnitelmia niin, että nuorelle yrittäjä- perheelle löytyisi sellainen tuotantosuunta tai sellaiset tuotannonhaarojen yhdistelmät, joilla saadaan kohtuullinen toimeentulo huomioimalla olemassa olevat tuotanto-olosuhteet, pellot ja metsä. Oleellinen osa tutkimusta oli työhön kuluva aika ja työhyvinvointi. Ensimmäisenä tehtävänä oli tutkia naudanlihantuotannon kannattavuutta nykyisellä tuotannolla, eli maitorotuisten lihanautojen kasvattamisella. Toisena vaihtoehtona vertailussa oli risteytyslihanautojen kasvattaminen. Kolmantena tutkittavana vaihtoehtona oli tilan tuotantosuunnan muuttami- nen kasvinviljely- ja klapituotantoon. Työn tarkoituksena oli kohdetilalla olevien realististen tuotantomahdollisuuksien hyödyntäminen niin, että palkka tehdystä työstä on riittävä ja sillä tulee kohtuullisesti toimeen. Tutkimus toteutettiin kohdetilalla case- eli tapaustutkimuksena ja kannattavuutta vertailtiin katetuottomenetelmän mukaisella taloussuunnitelmalla. Työhön kuluva aika laskettiin TTS-managerilla eläintenhoidon ja peltoviljelyn osalta. Klapituotantoon kuluva aika laskettiin siten, että työhön käytettiin kuusi tuntia päivässä viitenä päivänä viikossa lokakuun alusta huhtikuun loppuun. Keskeisimmät tulokset katetuottomenetelmän mukaisen taloussuunnitelman pohjalta olivat: maataloustulo eli yrittäjätulo ennen veroja oli paras risteytyslihanautoja kasvatettaessa ja kannattavuuskerroin, jossa tavoitteena oli 1, saavutettiin risteytyslihanautoja kasvatettaessa sekä kasvinviljely- ja klapituotannossa. Ajankäytöllisesti maitorotuisen lihakarjan ja risteytyslihakarjan työmenekki oli lähes samansuuruinen. Kasvinviljely- ja klapituotannon työmenekki oli pienin. Tilanpidon alkuvaiheessa yrittäjien kannattaa jatkaa lihakarjan kasvattamista lisäämällä risteytysliha nautojen osuutta sekä ottamalla klapituotantoa siihen rinnalle pikku hiljaa.An intense structural change is taking place in Finnish agriculture: small farms have closed down and the remaining farms are expanding. Some farms specialize and the others become multifunctional enterprises. The target of this thesis is to study the strategic plans of the subject farm in order to find such production sector or such combinations of production sectors, which enable a fair income by taking into consideration the existing production circumstances, fields and forest. An essential part of this study is the amount of working hours and work welfare. The first task was to study the profitability of the beef production within the present production, i.e. by raising dairy cattle based beef cattle. The other possibility taken into consideration in this comparison was the raising of cross-breeded beef cattle. The third possibility to be studied was the change of the production sector to plant and firewood production. The purpose of the thesis was to make use of the realistic production possibilities of the farm in such manner that wages from the work are adequate and that they enable a reasonable income. The study was implemented on the subject farm as a case study and the profitability was evaluated with the help of an economic planning based on contribution margin method. The time put into the work with the livestock and fields was counted by TTS-manager. The time used for fire- wood production was evaluated with the supposition that the work takes six hours a day five days a week from the beginning of October to the end of April. The central results on the basis of the economic planning based on contribution margin method were: Agricultural income, i.e. entrepreneurial income before taxes was the best when raising cross-breeded beef cattle and profitability ratio, the target figure of which was 1, was reached when raising cross-breeded beef cattle as well as in plant and firewood production. Raising of dairy cattle based beef cattle and cross-breeded beef cattle took nearly the same amount of working hours. In the comparison the plant and firewood production sector had the smallest amount of working hours. At the beginning of their farming it would be profitable for the entrepreneur family to continue the raising of beef cattle by increasing the amount of cross-breeded beef cattle as well as starting up with the firewood production little by little