Speech Acts On Trial

of speech act theory as a theoretical foundation for the design of information technology (IT). We pay special attention to the adaptation speech act theory has undergone when applied in the IT-field. One question we address concerns what happens when we import passive descriptive theories from other disciplines and use them as a basis in active design. The basic standpoint is that speech act theory may be useful, but only if one is aware of its shortcomings. By surveying various criticisms directed towards speech act based design along with extensions and alternative approaches we attempt to pinpoint these shortcomings. Our aim is to identify breakdowns of speech act based methods and discuss the need for further adaptation. This is done by the use of a framework, also presented in the chapter

Biologisk recipientkontroll vid Södra Cell Värö

Sedan 1983 övervakas fisksamhället utanför pappersmassafabriken Södra Cell Värö. Undersökningarna utförs genom provfiske med bottentrål i det havsområde där processvattnet strömmar ut (recipient). För att kunna göra relevanta tidsserieanalyser utförs även motsvarande provtagning i ett opåverkat område (referens). Årets fångst har främst dominerats av unga individer av olika torsk- och plattfiskarter. De vanligaste förekommande arterna i fisket är sandskädda och vitling. Flera av arterna har visat stigande antal sedan provtagningarna startade, särskilt i recipienten. Fjärsing, tungevar, svart smörbult, simkrabba och krabba har ökat i båda områdena. Kolja och slätvar har ökat i recipienten, men ingen trend har kunnat urskiljas i referensområdet för dessa arter. Till de arter som minskat i antal hör rödspätta och bergtunga, som båda visar en nedåtgående trend i referensområdet. Sett till den senaste tioårsperioden har torsk och rödspätta minskat i båda områdena. Sedan provfiskets början har artrikedomen ökat i båda områdena. Undersökningarna kunde inte påvisa någon negativ effekt på fisk till följd av Södra Cell Värös utsläpp. Uppvandringen av ålyngel i Viskan har dokumenterats med hjälp av fällor i åmynningen sedan 1971. Även om fångsten under säsongen 2013 var den högsta på åtta år så har det skett en stark nedgång i uppvandringen av ål sedan mitten av sjuttiotalet. Nedgången i Viskan har följt de trender som setts på andra platser i Europa och den bedöms inte ha något samband med verksamheten vid Södra Cell Värö. För att undersöka bottenförhållandena och djurlivet på och i anslutning till utsläppstuben har området filmats varje höst med en fjärrstyrd undervattensfarkost, en så kallad sjöuggla. Havsbotten i anslutning till tuben visade inte några tydliga tecken på syrebrist i årets filmning och djurlivet var inte förändrat jämfört med tidigare år

Biologisk recipientkontroll vid Ringhals kärnkraftverk

Kylvattenanvändningen vid Ringhals kärnkraftverk påverkar fisk- och skaldjurssamhället i olika steg. I det första steget genom utslagning av ägg, larver och större fisk som följer med det inkommande vattnet in i kraftverket och i ett andra steg genom att fiskens och skaldjurens miljö påverkas av det utkommande uppvärmda vattnet. Förekomsten av uppvärmt kylvatten vid utsläppet kan även bidra till att främmande invasiva arter etablerar sig i kustområdet. Under 2013 producerade Ringhals reaktorer R1, R2 och R4 elektricitet under hela året, med avbrott för årliga revisioner och kortare driftsstopp. Ringhals reaktor R3 var avstängd en längre period under sommaren i samband med revisonen. I kylvattenintaget utförs provtagning av fiskägg och fisklarver med Bongohåv för att övervaka förlusterna i kraftverket. Förekomsten av rötsimpelarver (Myoxocephalus scorpius) har minskat sedan provtagningen startade, 2013 fångades dock fler rötsimpelarver än tidigare under provtagningsserien. Förekomsten av tejstefisklarver (Pholis gunnellus) hade ökat något mellan 2012 och 2013. Håvning i intaget efter juvenil fisk är till stor del fokuserad på glasål (Anguilla anguilla). Glasålen har minskat kraftigt sedan 1980-talet. Minskningen av glasål beror på en tillbakagång i hela regionen och inte på att förlusten i intaget har lett till en lokal påverkan. Effekten av utgående uppvärmt kylvatten undersöks genom jämförande provfisken i två områden som båda påverkas av kylvattnet och ett opåverkat referensområde. Under april månad har diversiteten i fisksamhället minskat i det påverkade området, men inte i referensområdet, sannolikt som en följd av kylvattensutsläppet. Förekomsten av flera varmvattengynnade arter, bland annat ål (Anguilla anguilla), strandkrabba (Carcinus maenas) och skärsnultra (Symphodus melops) visar en uppåtgående trend i det kylvattenpåverkade området. Strandkrabba uppvisar även en ökande trend i referensområdet. För äkta tunga (Solea solea) var däremot trenden vikande i recipientområdet under aprilprovtagningen. Flera av de arter som gynnas Aqua reports 2014:2 av lägre vattentemperaturer fångas i lägre antal i recipientområdet. Mest tydligt var detta för rötsimpa (Myoxocephalus scorpius) och tånglake (Zoarches viviparus). Av de arter som gynnas av kallare vatten visade flera vikande trender i båda områdena. Endast skrubbskädda (Platichthys flesus) visade en ökande trend i referensområdet. För att påvisa förekomst av främmande arter genomförs dykkartering i fem områden utanför kraftverkets kylvattenutsläpp. Inga för regionen nya arter noterades under 2013, men tre för västkusten väletablerade främmande arter noterades. Dessa var japanskt jätteostron (Crassostrea gigas), rödalgen rödsvansing (Dasya baillouviana) samt en brunalg, sargassosnärja (Sargassum muticum)

An evolution of pontoon traps for cod fishing (Gadus morhua) in the southern Baltic Sea

With increasing seal populations in the Baltic Sea comes growing interaction between seals and coastal fisheries. The impact of seals, mainly grey seal (Halichoerus grypus), on fisheries can be reduced by implementing of seal-safe fishing gear, which hinders seal access to catches. One successful solution is the introduction of a modified seal-safe trap net, the pontoon trap. In this study, pontoon traps were modified for use in cod (Gadus morhua) fisheries in the southern Baltic Sea. Three aspects of the pontoon trap design were tested for their effects on catch rates: (1) leader net mesh size; (2) leader net length; and (3) fish chamber position. The greatest catch rates were obtained using a leader net with a 100 mm center-knot to center-knot mesh-size on a bottom-set fish chamber while there was no difference in cod catch rates in relation to leader net length. There was no seal-induced damaged cod in the pontoon traps during any of the trials. Cod catch rates using the pontoon trap were also compared to those of the cod gillnet fishery in the same area. The comparison showed that during specific fishing occasions, multiple pontoon traps may have similar catch rates to gillnets

Effects of fishery and environmental factors on a novel multispecies pot targeting European lobster (Homarus gammarus), Atlantic cod (Gadus morhua) and edible crab (Cancer pagurus)

Small-scale fisheries along the Swedish west coast are often operated by using small vessels, targeting multiple species by means of pots and gillnets. Fisheries using pots targeting shellfish such as European lobster (Homarus gammarus), and edible crab (Cancer pagurus) along the Swedish west coast have a relatively high economic value. However, gillnet fisheries targeting demersal fish are currently diminishing primarily due to depleted fish stocks and increased seal depredation. Small-scale fisheries are considered sustainable fisheries due to the use of selective gears and low energy consumption. To be able to retain and promote a sustainable small-scale fishery, there is a need to develop an economically viable fishery, where selective, seal-safe and sustainable gear is utilized. One potential way forward could be to develop a pot to be used for multiple target species traditionally caught in pots and gillnets. Since both shellfish and cod (Gadus morhua) can be caught in pots, the objective of this work was to develop a multispecies pot targeting lobster, edible crab and cod. Seven multi-species pots were developed and tested off the west coast of Sweden between 2015 and 2017. The catch rate, defined as catch per pot per day (CPUE) of lobster, edible crab and cod, was evaluated taking into regard fisheries-related variables such as pot type, bait, soak time, seal damage and abundance of species in the pot. The relative CPUE of lobster and cod was highest in larger pots with two chambers and three open entrances. The highest CPUE for lobster was 0.24 individuals per pot and the highest CPUE for cod was 0.17 individuals per pot. Pots with entrances equipped with funnels, preventing cod from escaping, also had a high cod CPUE (0.23 individuals per). The CPUE of crabs was not affected by pot type. For cod, lobster and crab, the CPUE significantly decreased with increasing soak time. Seal damage only occurred when cod were trapped in the pots and the CPUE of cod was higher in pots subjected to seal damage, indicating that seals raid pots specifically when cods are trapped inside

The effects of Contracaecum osculatum larvae on the growth of Atlantic cod (Gadus morhua)

Atlantic cod (Gadus morhua) from the Eastern Baltic stock have decreased in numbers and condition since the 1990′s. Among several causes, an increased prevalence and intensity of the nematode Contracaecum osculatum has been discussed. This increase has been attributed to a population increase of the parasites final host, the grey seal (Halichoerus grypus). Other studies have looked at the role of Contracaecum osculatum on cod growth and condition on recently caught cod, or done short term experimental studies in lab. This study instead investigated the importance of Contracaecum osculatum for cod growth in a sea pen based experiment, where cod were kept and fed in order to monitor growth. The results show that a higher density (number of nematodes per gram liver) decreases cod growth potential. If the number of nematodes exceeded 8 per gram liver cod did not grow in length, even when given generous amounts of food. Accounting for the lack of growth due to Contracaecum osculatum may improve stock assessments and increase the possibility to reach management targets

The devil is in the details: exploring how functionally distinct round goby is among native fish in the Baltic Sea

Understanding the characteristics and conditions that make non-indigenous species (NIS) successful at establishing in recipient communities is a key in determining their potential impacts on native species, as well as to improve management actions such as prevention of future invasions. The round goby (Neogobius melanostomus) is one of the most widespread non-indigenous fish species in the Northern Hemisphere, including the coastal zones of the Baltic Sea. The impacts of round goby in the Baltic Sea are pronounced and multifaceted, yet our knowledge regarding the underlying assembly processes determining its establishment is limited. To overcome this knowledge gap, we applied a trait-based approach to assess the degree of niche overlap and functional (trait) similarity between round goby and native fish species in coastal areas from the Baltic Sea, based on the functional distinctiveness metric. Our results show that round goby is generally quite similar (or not dissimilar) to the native fish of the regional species pool, at least in terms of its overall trait composition. Conversely, round goby demonstrates pronounced differences compared to the native community in its display of parental care and territorial behaviour. Such differences in individual traits could play an important role in round goby’s invasion success in the Baltic Sea, including its interactions with native species (e.g. competition). Our results and their potential implications may be highly relevant for conservation and management if integrated within existing risk assessment tools for biological invasions in order to prioritise and enhance the effectiveness of preventative actions towards the expansion of round goby

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AquaticVID: a low cost, extended battery life, plug-and-go video system for aquatic research

AquaticVID is a low-cost, long battery life video camera system for use in a wide-range of aquatic research applications. The system can be deployed for multiple day recording on a single charge, is submersible to depths of down to 950 m and can be constructed quickly using easily sourced off-the-shelf materials. The system is essentially ‘plug-and-go’, as assembly and preparation for deployment take