Papers by Antti Lappalainen
arXiv (Cornell University), Jun 17, 2022
Species distribution models (SDMs) are key tools in ecology, conservation and management of natur... more Species distribution models (SDMs) are key tools in ecology, conservation and management of natural resources. They are commonly trained by scientific survey data but, since surveys are expensive, there is a need for complementary sources of information to train them. To this end, several authors have proposed to use expert elicitation since local citizen and substance area experts can hold valuable information on species distributions. Expert knowledge has been incorporated within SDMs, for example, through informative priors. However, existing approaches pose challenges related to assessment of the reliability of the experts. Since expert knowledge is inherently subjective and prone to biases, we should optimally calibrate experts' assessments and make inference on their reliability. Moreover, demonstrated examples of improved species distribution predictions using expert elicitation compared to using only survey data are few as well. In this work, we propose a novel approach to use expert knowledge on species distribution within SDMs and demonstrate that it leads to significantly better predictions. First, we propose expert elicitation process where experts summarize their belief on a species occurrence proability with maps. Second, we collect survey data to calibrate the expert assessments. Third, we propose a hierarchical Bayesian model that combines the two information sources and can be used to make predictions over the study area. We apply our methods to study the distribution of spring spawning pikeperch larvae in a coastal area of the Gulf of Finland. According to our results, the expert information significantly improves species distribution predictions compared to predictions conditioned on survey data only. However, experts' reliability also varies considerably, and even generally reliable experts had spatially structured biases in their assessments. This suggests that expert elicitation can be an efficient tool, for example, in natural resources management and conservation area planning, but expert information should be analyzed with care and preferably calibrated.
Yksikkö/tutkimusohjelma Tutkimus-ja asiantuntijapalvelut / Itämeri-ohjelma Hyväksynyt Riitta Rahk... more Yksikkö/tutkimusohjelma Tutkimus-ja asiantuntijapalvelut / Itämeri-ohjelma Hyväksynyt Riitta Rahkonen, yksikönjohtaja, Tutkimus-ja asiantuntijapalvelut Tiivistelmä Ammattikalastus Raaseporin merialueella on vähentynyt ja vuonna 2010 alueella asui enää 23 saalista raportoinutta ammattikalastajaa, joista 20 haastateltiin tätä selvitystä varten syksyllä 2011. Kuha ja ahven olivat kaksi tärkeintä saalislajia alueen ammattikalastajille. Kummankin lajin kohdalla vapaa-ajankalastuksen saaliit Suomenlahdella ovat suuremmat kuin ammattikalastuksen saaliit. Ahvenen kohdalla ero on moninkertainen. Tammisaaren-Snappertunan alueella ammattikalastajien pääasiallinen pyydys oli verkko, Tenholan puolella verkkojen lisäksi myös rysät olivat tärkeitä pyydyksiä. Saaliskalojen vähyys sekä myös hylkeiden kalastukselle aiheuttamat haitat ja pyyntiin soveltuvien kalavesien huono saatavuus koettiin yleisimmin kalastuksen harjoittamista vaikeuttaviksi tekijöiksi. Noin puolet kalastajista oli kiinnostunut särkikalojen "poistopyynnistä". Kampela on vähentynyt Raaseporin alueella selvästi. Ahven-ja kuhakannat runsastuivat lounaisrannikolla 80luvulta alkaen, mutta selvää saaliin alenemista on myöhemmin tapahtunut verrattuna 1990-luvun lopun huippuvuosiin. Hauki-ja madesaaliit ovat vähentyneet. Siikasaaliit ovat kuitenkin olleet viime vuosikymmenen aikana tasaiset. Siika on ollut jo pitkään tärkeä istutuslaji Raaseporin alueella ja alueen siikasaaliista valtaosa lieneekin peräisin istutuksista. Muiden lajien kohdalla istutusten mahdollisia vaikutuksia alueelta saataviin saaliisiin on vaikea arvioida. Kalastusalueet ovat asettaneet verkoille solmuvälirajoituksia lähinnä kuhan kestävän kalastuksen turvaamiseksi. Kalastukselle haitallisiksi katsottujen harmaahylkeiden ja merimetsojen määrät läntisellä Suomenlahdella ovat olleet parin vuosikymmenen ajan kasvussa, mutta kummankin lajin kohdalla kasvu on aivan viime vuosina pysähtynyt tai jopa kääntynyt laskuun. Alueen vedet ovat voimakkaasti rehevöityneitä, mikä näkyy kalastuksessa selvimmin pyydysten voimakkaana likaantumisena, mutta rehevöitymisellä on ollut vaikutuksia myös alueen kalastoon. Kuhan ja hauen tärkeimmät lisääntymisalueet sijoittuvat sisälahdille. Selvityksen loppuun on koottu ehdotuksia toimenpiteiksi, jotka olisi mahdollista toteuttaa paikallisella tasolla ja joilla ammattikalastuksen toimintaedellytyksiä alueella voitaisiin parantaa. Suositukset koskevat kalastuksen säätelyä, istutuksia ja mahdollista istutuskokeilua, särkikalojen tehopyyntiä sekä hyljeongelman vähentämistä. Asiasanat ammattikalastus, kuha, ahven, kalastuksen säätely, Suomenlahti Julkaisun verkko-osoite
Suomen ympäristökeskus, 2020
The monitoring manual is a background report for Finland's monitoring programme under the marine ... more The monitoring manual is a background report for Finland's monitoring programme under the marine strategy. It describes all the monitoring activities under Finland's marine strategy. The monitoring manual presents is updated since the previous monitoring period 2014-2020 and it is valid from July 2020 to July 2026. The monitoring programme is regulated by the Act on the Organisation of River Basin Management and the Marine Strategy (272/2011) and the Government degree on the Organisation of the Development and Implementation of the Marine Strategy (980/2011). These are given to transpose the EU Marine strategy framework Directive (MSFD; 2008/56/ EU) to Finnish legislation. Finland's marine monitoring programme consists of 13 programmes and 44 subprogrammes. For the updated programme, four new programmes were added and several subprogrammes were supplemented due to new monitoring requirements, novel methods or altered conditions. New monitoring requirements were set by the updated annex III of the MSFD (2017/845/EU) and the new EU Commission Decision on criteria and methodological standards on good environmental status of marine waters and specifications and standardised methods for monitoring and assessment (2017/848/EU). This monitoring manual consists of three parts. Part I describes background information for the monitoring programme, Part II presents the monitoring activities and Part III includes discussion on costs, development needs and conclusions. The programmes reflect the agreed definitions on the EU level and the subprogrammes reflect the respective indicative list of subprogrammes. The monitoring programme includes parameters of state of the marine environment, elements of marine ecosystem as well as human pressures affecting the marine ecosystem. The subprogrammes describe monitored parameters (state or pressures), the monitoring frequency, indicators using the information, data management as well as links to the qualitative descriptors and criteria of the EU MSFD.
Along the Finnish coast, the Gulf Olympia paired ichthyoplankton samplers have been widely used f... more Along the Finnish coast, the Gulf Olympia paired ichthyoplankton samplers have been widely used for collecting early life stages of pelagic fish, e.g. within the Finnish Inventory Programme for Marine Underwater Environment (VELMU), aiming to localize larval habitats. The aim of this study was to examine how prevailing conditions during the sampling period impact the sampling efficiency and the data obtained with the Gulf Olympia samplers. The study was conducted in the Skinnarfjärden-Köklotfjärden Bay on the west coast of Finland, within the northern Kvarken Archipelago in the northern Baltic Sea. Sampling was carried out along 10 randomly pre-allocated transects during 5 days between the 6th and 12th of June 2017. Effect of sampling depth (0.5 m and 1.0 m), wave height, light availability and sampling time (morning / afternoon) on larval density of perch (Perca fluviatilis) and smelt (Osmerus eperlanus) was studied using linear mixed model analysis. Sampling depth affected the results, as sampling at 0.5 m yielded 6 times more perch and 1.3 times more smelt larvae than at 1.0 m depth. Wave height was also found to correlate positively with larval abundance of both perch and smelt at depth of 0.5 m, with a 16-fold and 8-fold increase in perch and smelt density respectively, following a change in wave height from 0 m to 0.3 m. Both perch and smelt larval density correlated positively with increasing levels of light, while no significant effect of sampling time was found. Finally, we give recommendations for future sampling settings. This study was carried out as a part of the VELMU 2 programme, funded by the Ministry of the Environment and the Ministry of Agriculture and Forestry of Finland.
The material in this report may be reused using the recommended citation. ICES may only grant usa... more The material in this report may be reused using the recommended citation. ICES may only grant usage rights of information, data, images, graphs, etc. of which it has ownership. For other third-party material cited in this report, you must contact the original copyright holder for permission. For citation of datasets or use of data to be included in other databases, please refer to the latest ICES data policy on the ICES website. All extracts must be acknowledged. For other reproduction requests please contact the General Secretary. For permission to reproduce material from this publication, please apply to the General Secretary. The document is a report of an Expert Group under the auspices of the International Council for the Exploration of the Sea and does not necessarily represent the views of the Council.
Ecological compensations in coastal and open sea areas of the Baltic Sea The need to protect biod... more Ecological compensations in coastal and open sea areas of the Baltic Sea The need to protect biodiversity is increasing worldwide. Human activities, especially eutrophication, have strongly and adversely impacted the marine environment in the watershed, coastal and open sea areas of the Baltic Sea. The existing marine protection area (MPA) network is a central component in sustaining the biodiversity values of the Baltic Sea. However, even though the MPA network protects important marine and coastal habitats and species, further measures are needed to reduce the rapid decline of biodiversity. One additional measure to halt biodiversity loss is ecological compensation or offsetting, where damage caused by human activity is compensated by restoring or protecting biodiversity elsewhere. The aim of ecological compensations is to produce ecological benefits to ecosystems (and/or species) and secure the essential ecosystem services in situations where human activities cause degradation to natural environments. General recommendation is that ecological compensations should be used as a final measure to minimize biodiversity loss. According to the mitigation hierarchy avoidance, mitigation and restoration on site should all be applied to minimize the damages prior to compensation. Furthermore, compensations should be measurable, permanent and of similar magnitude as the damages. The impact should be estimated based on ecological criteria, which separates ecological compensations from for example nutrient or carbon compensations. This report considers potentially usable measures that can be taken in the Baltic Sea watershed and coastal areas when planning ecological compensation. The compensation of marine ecological functions and values can be more complicated than compensations in terrestrial environments, because marine ecosystems are dynamically and three dimensionally connected ecological entities, which are characterized by strong spatio-temporal connectivity. The interconnectedness of terrestrial and marine systems is taken into account: the report includes measures for the watershed area because they can form an important part of a holistic approach in offsetting planning: reducing the effects of eutrophication on a local level by restricting the inflow of nutrients from the watershed can increase chances to actually achieve the offsetting goals than if only local coastal or marine measures are taken. Furthermore, concrete compensation measures are presented for sheltered and open coastal areas and different underwater habitats, including key habitats for fish. Finally, compensation measures for individual species are discussed shortly, although only a limited number of examples exist. Most of the measures presented in this report can be utilized also in other levels of the mitigation hierarchy when reducing and limiting the effects of human activities. It is thus essential that the chosen measures are planned and used to offset ecological functions and values and the planning, realisation and monitoring of the whole compensation procedure is well defined and carried out according to the principles of the mitigation hierarchy.
Catch per unit effort (CPUE) indices, derived from daily logbooks of open sea fisheries or from s... more Catch per unit effort (CPUE) indices, derived from daily logbooks of open sea fisheries or from standard gill-net surveys have traditionally been used as a source of information on trends in fish stock biomass or abundance. Nowadays, the systematic collection of catch and effort data from coastal small-scale fisheries has gradually been launched as well, e.g., in the Baltic Sea. The data from coastal fisheries is typically collected in monthly logbooks. We demonstrate that raw CPUEs, CPUEs based on subsetted data and CPUE indices based on linear mixed models (LMMs) from coastal gill-net fishery data covering a 20-year period yield different results on trends in abundance. The use of advanced counting methods is recommended to reduce the amount of the annual variation not attributable to changes in abundance. Thereafter, CPUE indices based on the monthly logbook data can produce valuable and cost-effective information on fish abundance.
Yksikkö/tutkimusohjelma Tutkimus-ja asiantuntijapalvelut Hyväksynyt Nina Peuhkuri Tiivistelmä Kal... more Yksikkö/tutkimusohjelma Tutkimus-ja asiantuntijapalvelut Hyväksynyt Nina Peuhkuri Tiivistelmä Kalataloustarkkailujen yhteydessä tehtävien koekalastusten tavoitteena on seurata mm. jokirakentamisen, jätevesipäästöjen, turvetuotannon, ruoppausten, perkausten tai kunnostusten vaikutuksia kalastoon tietyllä alueella. Kalastossa tapahtuvien muutosten arviointiin sekä kalanäytteiden keräämiseen järvillä ja rannikkoalueilla käytetään verkkokoekalastusta. Virtavesien koekalastuksissa käytetään sähkökalastusta. Tässä raportissa esitetään ohjeet standardinmukaisiin koekalastuksiin. Järvien verkkokoekalastuksissa noudatetaan eurooppalaista CEN-standardia (SFS-EN 14757) ja käytetään NORDIC-verkkoa. Pyyntivuorokausien määrä riippuu tutkittavan vesialueen pinta-alasta ja syvyyssuhteista. Verkkoöiden määrä jaetaan eri syvyysvyöhykkeille (< 3 m, 3-10 m, 10-20 m ja > 20 m) niiden pinta-alojen mukaisessa suhteessa. Järvialueiden verkkokoekalastuksissa käytetään pinta-, välivesi-ja pohjaverkkoja. Rannikkovesien verkkokoekalastuksissa käytetään COASTAL-verkkoa. Rannikkoalueilla verkkoöiden lukumäärän yhdellä alueella tulisi olla 30-45. Rannikkoalueella verkkokoekalastuksissa käytetään ainoastaan pohjaverkkoja. Verkkoöiden määrä jaetaan tasan kolmelle eri syvyysvyöhykkeelle (< 3 m, 3-6 m ja 6-10 m). Järvillä ja rannikkovesissä verkkokoekalastukset tehdään kesäkerrostuneisuuden aikana. Pyyntipaikkojen valinta tehdään satunnaisotannalla. Pyyntiajaksi suositellaan verkkojen laskua illan suussa ja nostoa seuraavana aamuna, jolloin pyyntiajaksi tulee n. 12 tuntia. Verkkokoekalastuksissa saalis käsitellään verkko-ja solmuvälikohtaisesti. Sähkökalastuksessa noudatetaan eurooppalaista CEN-standardia (SFS-EN 14011). Sähkökalastukset tehdään loppukesällä ja alkusyksyllä, jolloin taimenen ja lohen saman vuoden poikaset ovat pyydystettävissä. Kun sähkökalastus kuuluu vesienhoidon seurantaan, käytetään yhden poistopyynnin menetelmää. Suositeltava kalastettavan alueen koko on vähintään 300 m 2 , kuitenkin mieluiten yli 450 m 2. Alle 15 m leveissä joissa kalastetaan koko uoman leveys, suurissa yli 15 m leveissä joissa kalastetaan ranta-alue joko toiselta tai molemmilta puolilta jokea. Suosituksena on, että kaikki kalat mitataan ja punnitaan yksitellen. Koekalastusrekisteri on Riista-ja kalatalouden tutkimuslaitoksen (RKTL) hallinnoima ja Suomen ympäristökeskuksen (SYKE) ylläpitämä tietokantarekisteri kaikille maassamme tehdyille standardinmukaisille verkkoja sähkökoekalastuksille. Rekisteri ei ole kaikille avoin vaan sen käyttäjä tarvitsee käyttöoikeuden.
Socio-Environmental Systems Modelling, 2019
Oceans around the world are threatened by human pressures. Ecological indicators are useful tools... more Oceans around the world are threatened by human pressures. Ecological indicators are useful tools in understanding complex systems and their changes caused by human pressures, and the information they offer is also needed for ecosystem-based management. Integrated assessments combine information produced by several indicators at different spatial scales and thus offer a more holistic view of the status of the ecosystem. In this study, we evaluate the integration of biodiversity indicators at different spatial scales in two study areas in the Baltic Sea: Gulf of Finland and Bothnian Sea. By producing time series of the indicators and integrated assessments, we study the historical changes in the overall marine biodiversity status, and the impact of data availability, indicator selection, and choice of spatial assessment units on the status assessment. The integrated assessments are produced using the Biodiversity Assessment Tool (BEAT 3.0) and following the procedure of the HELCOM in...
Estuarine, Coastal and Shelf Science, 2018
Many coastal and offshore fish species are highly dependent on specific habitat types for populat... more Many coastal and offshore fish species are highly dependent on specific habitat types for population maintenance. In the Baltic Sea, shallow productive habitats in the coastal zone such as wetlands, vegetated flads/lagoons and sheltered bays as well as more exposed rocky and sandy areas are utilised by fish across many life history stages including spawning, juvenile development, feeding and migration. Although there is general consensus about the critical importance of these essential fish habitats (EFH) for fish production along the coast, direct quantitative evidence for their specific roles in population growth and maintenance is still scarce. Nevertheless, for some coastal waters and substrates necessary to any life-stage of fish for spawning, breeding, feeding or growth to maturity (Benaka et al. 1999, Rosenberg et al. 2000). In this respect, the term waters include all aquatic coastal areas (down to a maximum depth of 10-20 m) and their physical, chemical, and biological properties, whereas substrates include surfaces and their associated biological communities that make them suitable as fish habitats (Rosenberg et al. 2000). Coastal EFH are thus comprised of juvenile growth areas, foraging areas, reproduction areas and migratory routes. While the latter three are of direct importance for fisheries, by offering high catches or value per fishing effort (Airoldi and Beck 2007, Seitz et al. 2014), the former one is a step required to produce recruits to replenish the fishery (Beck et al. 2001). Fishing may, however, be challenging for the sustainable management of some coastal EFH, not only as some fishing practices are detrimental to the habitats per se, but also because targeted extraction of species from the general marine ecosystem may indirectly influence the habitats by altering predator-prey interactions (
Scientific reports, Jan 21, 2018
Climate change is predicted to cause a freshening of the Baltic Sea, facilitating range expansion... more Climate change is predicted to cause a freshening of the Baltic Sea, facilitating range expansions of freshwater species and contractions of marine. Resident marine flounders (Platichthys flesus) and expansive freshwater roach (Rutilus rutilus) are dominant consumers in the Baltic Sea sublittoral where they occur in partial sympatry. By comparing patterns of resource use by flounders and roach along a declining resource gradient of blue mussels (Mytilus trossulus) our aim was to explore predator functional responses and the degree of trophic overlap. Understanding the nature of density-dependent prey acquisition has important implications for predicting population dynamics of both predators and their shared prey. Results showed a highly specialized diet for both species, high reliance on blue mussels throughout the range, similar prey size preference and high trophic overlap. Highest overlap occurred where blue mussels were abundant but overlap was also high where they were scarce. ...
Rannikkovesien tila huolestuttava Uudenmaan rannikkoalueet ovat voimakkaasti rehevöityneet. Saari... more Rannikkovesien tila huolestuttava Uudenmaan rannikkoalueet ovat voimakkaasti rehevöityneet. Saaristossa alusveden happipitoisuudet kääntyivät yleisesti jyrkkään laskuun 2000-luvulla ja tänä päivänä saariston pohjien pinta-alasta ja myös vesitilavuudesta huomattava osa on loppukesällä pohjaeläimille, kaloille ja eläinplanktonille elinkelvotonta happivajeen takia. Tapahtuneet muutokset ovat parantaneet useiden särkikalojen lisääntymisolosuhteita sisälahdilla samalla kun monien muiden kalalajien elinolosuhteet ulompana saaristossa ovat heikentyneet. Hapettomuudesta johtuva sisäinen ravinnekuormitus lienee tärkeä syy sille, että Uudenmaan saaristoalueiden vesien tilassa ei ole havaittavissa kohenemisen merkkejä. Käytännössä kotimaisen ravinnekuormituksen vähentämistoimenpiteet ovat olleet liian tehottomia. Uudenmaan saaristoalueet ovat voimakkaasti rehevöityneitä Vesienhoitolain mukaisessa pintaveden ekologisessa laatuluokituksessa Uudenmaan saaristo-ja rannikkovesien tilaa kuvataan tyydyttäväksi, välttäväksi ja paikoin jopa huonoksi (kuva 1). Vesialueiden tilaa heikentää rehevöityminen. Syynä on ihmistoiminnan aiheuttama voimakas ja pitkäaikainen ravinnekuormitus, jonka seurauksena vesiin on päätynyt liikaa typpeä ja fosforia.
Fisheries Research, 2016
In the Baltic Sea, the pikeperch is one of the commercially important coastal fish species. Most ... more In the Baltic Sea, the pikeperch is one of the commercially important coastal fish species. Most of the local pikeperch stocks in this area can be classified as data-limited. There is an increasing need to monitor the state of all commercial fish stocks in European waters due to the EU Marine Strategy Framework Directive (MSFD). Proper stock assessment is not required in all cases, and alternative and less data demanding approaches and indicators can also be applied. In this study, we combined data on three of the best-studied coastal pikeperch stocks in the northern Baltic Sea to evaluate the performance of length at maturity indicators. A connection was found between intensive selective fishing and the length at maturity (TL50) of female pikeperch. Power analysis indicated that a sample size of 200-400 females, or around 35-70 samples per year, produces reasonable and almost maximal precision when determining the six-year mean TL50 for a stock. Our analysis also demonstrated that in cases where a monitored parameter is annually variable, an increase in the annual sample size does not continuously yield higher precision in the long-term mean, but it is crucial that samples are collected annually. We conclude that TL50 is a promising and cost-efficient indicator of the effects of fisheries on the maturation of coastal pikeperch stocks. This indicator could be further tested after a few years when more data become available.
3 1. Introduction 4 2. Materials and methods 5 3. Results 6 4. Discussion 9 5. Conclusions 12 6. ... more 3 1. Introduction 4 2. Materials and methods 5 3. Results 6 4. Discussion 9 5. Conclusions 12 6. References
The Pechenganickel smelters in Nikel and Zapoljarnyi, northwestern Kola Peninsula, have been amon... more The Pechenganickel smelters in Nikel and Zapoljarnyi, northwestern Kola Peninsula, have been among the world's largest point sources of SO 2 , Ni and Cu emissions. In order to examine the effects of airborne emissions, the water quality of 35 small lakes and brooks in Finland, Norway and Russia, 1-50 km from the smelters, was surveyed, and fish of stony shores of these lakes and brooks were sampled by electrofishing in 2004 or 2005. The results demonstrated that in the study area the airborne emissions of the smelters have not caused any widespread damage to fish populations even in the most sensitive small waters. The small waters close to the smelters (roughly within a 10 km radius) are well buffered against the effects of high sulphate deposition. Extremely high concentrations of the heavy metals Ni and Cu, however, are a local threat to biota in small waters there, and a few lakes that have apparently lost their fish populations were found. In the border area of Russia, Norway and Finland, acidification is currently only a problem in some very small and sensitive waters located in the local highland areas, 15-50 km from the smelters. There, lakes with a low buffering capacity (alkalinity < 0.05 mmol l-1) can be found and some fish populations, mainly minnows, have probably been lost. The SO 2 emissions from the smelters have declined to approximately one third of the maximum level in the late 1970s, and this can be seen in a general recovery of the buffering capacity of small lakes such as those in the Finnish border region, 40-50 km west of the smelters.
Marine Ecology Progress Series, 2006
Predation is a key trophic component with a potentially large influence on rocky shore community ... more Predation is a key trophic component with a potentially large influence on rocky shore community organization. We studied prey size selection by roach Rutilus rutilus, feeding on blue mussels Mytilus edulis in the northeastern Baltic Sea. In this region, roach feed extensively on abundant populations of blue mussels living at the very edge of their range primarily set by low salinity conditions. The study area is characterised by a marked decline in mean mussel size from the saltier west to the less salty east. We predicted that average prey size of roach would decrease with decreasing availability of larger prey but increase with increasing size of the predator. The size of mussels ingested by roach ranged from 2 to 28 mm, largely covering the size distribution of blue mussels in the area. In accordance with our prediction, body size of the predator was the foremost factor determining patterns of prey selection and mean prey size increased steadily with increasing size of the predator. Roach were size selective, preferring median and large mussels in proportions different from their accessibility in the habitat. Contrary to our expectations, no differences between the areas were seen regarding prey size selection. These results contrast with optimal foraging theory predicting that predators under higher prey densities decrease the proportion of less profitable prey. Our results suggest that roach have the potential to significantly affect the blue mussel dynamics in areas with poor prey availability and we predict that ongoing environmental change in the Baltic will likely increase its impact.
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Papers by Antti Lappalainen