Developing spatial prioritisation strategies to maximise conservation impact

Despite exponential increases in the size, number, and coverage of protected areas (PAs), biodiversity continues to decline worldwide. Additionally, emerging evidence shows that PAs are often located in 'residual' areas, locations with minimal value for extractive activities, such as agriculture, development, mining and fishing. Over recent decades, systematic conservation planning (SCP) has developed new and sophisticated methods for ensuring that protected areas are complementary and representative, so that PA networks avoid redundancy and maximise biodiversity within their bounds. However, the SCP literature has few analyses that aim to maximise conservation impact. Impact is measured as the difference in biodiversity outcomes that occur when a given conservation intervention is applied, compared to when it is not (referred to as a 'counterfactual' scenario). As a result, many modern approaches to SCP have questionable impact, and might do little to counteract residual biases and ongoing biodiversity declines. The goal of my thesis is develop methods for estimating impact in SCP, and to use these methods to compare alternative spatial prioritisation strategies. To achieve this goal I set three objectives: 1. Establish a framework for using counterfactual-based impact estimation in conservation planning 2. Estimate and compare the impact of currently widespread conservation prioritisation strategies 3. Develop evidence-based spatial prioritisation strategies (i.e. 'rules of thumb') for cost effectively maximising impact in conservation planning In the first chapter, I introduce the concept of systematic conservation planning, and discuss modern approaches to conservation impact evaluation. I then identify four key knowledge gaps with respect to incorporating impact evaluation into conservation planning using counterfactual methods: (1) What methods can be used to implement counterfactual scenarios and estimate impact in spatial conservation prioritisation? (2) How effective are modern approaches to spatial conservation prioritisation at achieving impact? (3) What is the spatial relationship between threats and costs, and how does this affect conservation prioritisation to maximise impact? (4) How should we prioritise areas for conservation based on spatial patterns of costs, biodiversity, and threats? In the second chapter, I first address Objective 1 by developing a theoretical model to explore how the impact of alternative prioritisation strategies, compared to a counterfactual, can vary according to various factors. I compare two alternative prioritisation strategies: protecting high-threat frontier areas, or low-threat wilderness areas. I explore how the relative efficacy of either strategy compared to the counterfactual scenario varies depending on spatial patterns of threats, biodiversity values, conservation costs, timeframes within which impacts are measured, rates of biodiversity recovery, and temporal changes in threats. In doing so, this chapter also contributes to Objective 3, by identifying circumstances under which either frontier prioritisation, wilderness prioritisation, or a combination of both are likely to be most effective. In the third chapter, I further contribute to Objective 3 by aiming to quantify the spatial relationship between acquisition costs and threats to biodiversity using empirical data in a conservation landscape. As I show in the prior chapter, this spatial distribution has a large influence on the cost-efficiency of any given prioritisation strategy. In this chapter, I use high-resolution datasets of rates of vegetation clearance in Queensland, Australia. I then combine this data with land sales transactions, land valuations, and agricultural profitability to examine the spatial relationship. I then use a classic economic model to explore the potential drivers behind this relationship. I found that counter to what is widely assumed in conservation science, there is no clear spatial relationship between rates of land clearing and acquisition costs, and the relationship displays enormous variability. As a result, the landscape appears to contain a large number of sites with relatively low cost and potential for high impact. In the fourth chapter, I address all three objectives by implementing an ex post method to measure counterfactual outcomes and estimate impacts for several alternative prioritisation strategies. This chapter also uses the case study of Queensland, Australia. With the ex post method, the counterfactual scenario is measured using historical changes in vegetation in a landscape with no protected areas. I then retrospectively implement alternative prioritisation strategies and predict how outcomes might have differed compared to the counterfactual. Specifically, I compare four alternative prioritisation strategies: cost minimisation; threat prioritisation and cost minimisation; representation and cost minimisation; and representation, threat prioritisation and cost minimisation. These alternative strategies represent the extremes of how much importance should be placed on costs, threats and biodiversity when aiming to maximise impact. I find that the most effective strategy to maximise impact is to prioritise highthreat locations, and that aiming to achieve representation targets, a widely adopted practice in conservation planning, can be counter-productive to achieving impact. In the fifth chapter, I provide an alternative method to estimating impacts, which is to use ex ante predictions of expected outcomes in counterfactual scenarios and when alternative strategies are implemented. In this chapter, I estimate the impact of several strategies on the coral reefs of Micronesia: frontier prioritisation; wilderness prioritisation; representation; and representation with connectivity. This chapter complements the previous chapter by providing a method for estimating impacts when historical data on changes in biodiversity are unavailable, and when aiming to estimate impacts over long timeframes. Importantly, this chapter incorporates an additional component to measuring impact, which is to compare all strategies to a 'best-case' scenario, where biodiversity outcomes are known and impact can be optimised. Comparing strategies to a counterfactual and best-case allow absolute impacts to be measured. In this chapter I also find that the most effective strategy is generally to prioritise high-threat frontier areas, and that representation targets can be counterproductive to maximising impact. In achieving the above objectives and addressing the respective knowledge gaps, my thesis provides an important contribution towards incorporating counterfactual-based impact estimation in conservation planning. The global protected area network is expanding at an exponential rate, yet little is known about how well the strategies to spatially allocate these protected areas achieve positive conservation impacts. Given the severity and imminence of global biodiversity declines, it is essential that we develop an evidence base from which conservation policy and practice can draw upon to ensure that future conservation efforts can efficiently maximise impact and prevent further declines

Ecological connectivity in marine protected areas in Swedish Baltic coastal waters - A coherence assessment

The Department of Aquatic Resources at the Swedish University of Agricultural Sciences (SLU Aqua) was commissioned by the Swedish Agency for Marine and Water Management to assess the ecological coherence of the marine protected area (MPA) network along the Swedish Baltic Sea coast, focusing on ecological connectivity and representativity, and species performing active migrations. The study also aimed to test the influence of anthropogenic pressures on connectivity and identify areas for expansion of the existing MPA network to maximise connectivity in the region. This report is the first to assess large-scale connectivity and ecological coherence of the MPA network in the Baltic Sea with a focus on coastal habitat-forming vegetation and fish species with active dispersal. Information on dispersal/migration distances was combined with species distribution models to produce connectivity maps. To align the coherence analyses with the conservation targets specified by responsible authorities, we included the nested targets for specific species ("preciserade bevarandevärden” in Swedish) listed within the Swedish framework for MPAs. Fish species like eel, salmon and trout, as well as birds and seals, which are also listed as nested targets, were not included in our analyses, since connectivity models of these long-distance migrants would be redundant as they do not affect the more small-scale connectivity patterns that are in focus in this study. Hotspot areas for connectivity were identified, and these were generally concentrated in a few, relatively small areas. These hotspot areas are, however, highly susceptible to coastal development and human activities, as they are often situated in bays, inlets and topographically complex archipelagos. Anthropogenic pressures, in this case physical disturbance, had a relatively large predicted impact on connectivity, particularly on certain species. The majority of these species are of freshwater origin and have shorter migration distances (e.g. crucian carp, roach, common rudd, common bream/silver bream, and common bleak) than marine species like cod, flounder and herring, which perform long-distance migrations between open sea and coastal areas as part of their life cycle. Also large predatory fish like pike, pike-perch and perch, as well as habitat-forming submerged aquatic vegetation (SAV), showed a pronounced decrease in connectivity when incorporating physical disturbance into the models. This may be explained by most human pressures being concentrated along the coastline, often in shallow sheltered bays and inlets where human development coincides with sensitive vegetated habitats and important breeding, spawning, nursery and feeding grounds for fish. Connectivity is reduced when habitats become fragmented or diminished and populations become smaller and more isolated. This may in turn have consequences on genetic diversity, viability of populations and ultimately ecosystem functioning. Representativity of habitats; i.e. amount of habitat protected, was below what is generally scientifically recommended and the new target of 30% protection by 2030 in the EU Biodiversity Strategy for all but three species (of 30 in total). Representativity was very poor regarding strict MPAs, an average of 2% across species. The target according to the EU Biodiversity Strategy is 10% strict protection. Similar results were found for connectivity where the amount connected habitat within MPAs was low. MPAs in the study area were sufficiently spaced (distance apart), but dominated by MPAs of small size. Priority areas with high connectivity (identified by the spatial prioritization software prioritizr) were insufficiently protected and the connectivity of the network could be greatly improved with targeted protection in just a few important locations. Areas that are well connected locally, but are isolated from other priority areas, are especially important to protect as they are critical to connectivity of the network. Regulations within the MPA network in Swedish Baltic Sea coastal waters are generally weak, particularly in the priority areas. Applying an ecosystem-based management approach and including stronger regulations of fisheries and of activities causing local physical disturbance in parts of the MPA network is encouraged in order to reach conservation goals. The results from this study can be used to improve planning and management of the Baltic Sea MPA network, marine spatial planning in the region and improving the green infrastructure, securing important ecosystem services for future generations

Costs are not necessarily correlated with threats in conservation landscapes

The priority of an area for conservation is determined by three primary factors: its biodiversity value, the level of threat it is facing, and its cost. Although much attention has been paid to the spatial relationship between biodiversity value and threats, and between biodiversity value and costs, little is known about how costs and threats are spatially correlated. The orthodox assumption in conservation science is that costs and threats are positively correlated. Here, we adapt a classic economic theory of land use to explain how conservation scientists came to expect a positive correlation between costs and threats. We then use high‐resolution, ground‐truthed datasets of land sales and habitat clearance to show that this assumption is false in the state of Queensland, Australia. Our results provide an empirical counterargument to a widespread assumption in conservation science, and illustrate why spatial prioritization needs to include independent measures of costs and threats

Long-term effects of no-take zones in Swedish waters

Marine protected areas (MPAs) are increasingly established worldwide to protect and restore degraded ecosystems. However, the level of protection varies among MPAs and has been found to affect the outcome of the closure. In no-take zones (NTZs), no fishing or extraction of marine organisms is allowed. The EU Commission recently committed to protect 30% of European waters by 2030 through the updated Biodiversity Strategy. Importantly, one third of these 30% should be of strict protection. Exactly what is meant by strict protection is not entirely clear, but fishing would likely have to be fully or largely prohibited in these areas. This new target for strictly protected areas highlights the need to evaluate the ecological effects of NTZs, particularly in regions like northern Europe where such evaluations are scarce. The Swedish NTZs made up approximately two thirds of the total areal extent of NTZs in Europe a decade ago. Given that these areas have been closed for at least 10 years and can provide insights into long-term effects of NTZs on fish and ecosystems, they are of broad interest in light of the new 10% strict protection by 2030 commitment by EU member states.In total, eight NTZs in Swedish coastal and offshore waters were evaluated in the current report, with respect to primarily the responses of focal species for the conservation measure, but in some of the areas also ecosystem responses. Five of the NTZs were established in 2009-2011, as part of a government commission, while the other three had been established earlier. The results of the evaluations are presented in a synthesis and also in separate, more detailed chapters for each of the eight NTZs. Overall, the results suggest that NTZs can increase abundances and biomasses of fish and decapod crustaceans, given that the closed areas are strategically placed and of an appropriate size in relation to the life cycle of the focal species. A meta-regression of the effects on focal species of the NTZs showed that CPUE was on average 2.6 times higher after three years of protection, and 3.8 times higher than in the fished reference areas after six years of protection. The proportion of old and large individuals increased in most NTZs, and thereby also the reproductive potential of populations. The increase in abundance of large predatory fish also likely contributed to restoring ecosystem functions, such as top-down control. These effects appeared after a 5-year period and in many cases remained and continued to increase in the longer term (>10 years). In the two areas where cod was the focal species of the NTZs, positive responses were weak, likely as an effect of long-term past, and in the Kattegat still present, recruitment overfishing. In the Baltic Sea, predation by grey seal and cormorant was in some cases so high that it likely counteracted the positive effects of removing fisheries and led to stock declines in the NTZs. In most cases, the introduction of the NTZs has likely decreased the total fishing effort rather than displacing it to adjacent areas. In the Kattegat NTZ, however, the purpose was explicitly to displace an unselective coastal mixed bottom-trawl fishery targeting Norway lobster and flatfish to areas where the bycatches of mature cod were smaller. In two areas that were reopened to fishing after 5 years, the positive effects of the NTZs on fish stocks eroded quickly to pre-closure levels despite that the areas remained closed during the spawning period, highlighting that permanent closures may be necessary to maintain positive effects.We conclude from the Swedish case studies that NTZs may well function as a complement to other fisheries management measures, such as catch, effort and gear regulations. The experiences from the current evaluation show that NTZs can be an important tool for fisheries management especially for local coastal fish populations and areas with mixed fisheries, as well as in cases where there is a need to counteract adverse ecosystem effects of fishing. NTZs are also needed as reference for marine environmental management, and for understanding the effects of fishing on fish populations and other ecosystem components in relation to other pressures. MPAs where the protection of both fish and their habitats is combined may be an important instrument for ecosystembased management, where the recovery of large predatory fish may lead to a restoration of important ecosystem functions and contribute to improving decayed habitats.With the new Biodiversity Strategy, EUs level of ambition for marine conservation increases significantly, with the goal of 30% of coastal and marine waters protected by 2030, and, importantly, one third of these areas being strictly protected. From a conservation perspective, rare, sensitive and/or charismatic species or habitats are often in focus when designating MPAs, and displacement of fisheries is then considered an unwanted side effect. However, if the establishment of strictly protected areas also aims to rebuild fish stocks, these MPAs should be placed in heavily fished areas and designed to protect depleted populations by accounting for their home ranges to generate positive outcomes. Thus, extensive displacement of fisheries is required to reach benefits for depleted populations, and need to be accounted for e.g. by specific regulations outside the strictly protected areas. These new extensive EU goals for MPA establishment pose a challenge for management, but at the same time offer an opportunity to bridge the current gap between conservation and fisheries management

Costs are not necessarily correlated with threats in conservation landscapes

The priority of an area for conservation is determined by three primary factors: its biodiversity value, the level of threat it is facing, and its cost. Although much attention has been paid to the spatial relationship between biodiversity value and threats, and between biodiversity value and costs, little is known about how costs and threats are spatially correlated. The orthodox assumption in conservation science is that costs and threats are positively correlated. Here, we adapt a classic economic theory of land use to explain how conservation scientists came to expect a positive correlation between costs and threats. We then use high‐resolution, ground‐truthed datasets of land sales and habitat clearance to show that this assumption is false in the state of Queensland, Australia. Our results provide an empirical counterargument to a widespread assumption in conservation science, and illustrate why spatial prioritization needs to include independent measures of costs and threats

Konnektivitet och fysisk påverkan i kustvatten

Konnektivitet i kustvatten beskrivs som möjligheten för djur, växter, sediment och organiskt material att sprida sig och passera fritt mellan det öppna havet och kusten, längsgående i kustområden och mellan kustområden och inlandsvatten. Då konnektiviteten har en betydande och bred påverkan på det biologiska, fysikalisk-kemiska, och det hydromorfologiska tillståndet i kustoch havsmiljön, ingår den som en kvalitetsfaktor för bedömning av ekologisk status av ytvatten i kustzonen. Beskrivningen av konnektivitet och hur den ska bedömas i kustzonen är knapphändig i Havs- och vattenmyndighetens föreskrifter (HVMFS 2019:25). Institutionen för akvatiska resurser vid SLU har därför fått i uppdrag att ge förslag på information om biologisk konnektivitet som rör växter och djur som kan ingå i en revidering av dessa föreskrifter, samt ta fram ett kunskapsunderlag om konnektivitet och fysisk störning i kustzonen. I uppdraget har även ingått att analysera hur fysisk störning påverkar konnektivitet för fisk i både Skagerraks, Kattegatts och Östersjöns kustområden.Vid genomgång av föreskrifterna noterade vi att de saknar information om biologiska aspekter av konnektivitet och vilka rumsliga skalor man ska beakta. De nuvarande bedömningsgrunderna tar inte tillräcklig hänsyn till att konnektivitet antingen kan ske genom aktiv migration av organismer, såväl vuxna som juvenila, eller genom passiv spridning via larver, ägg, sporer, frön och fragment (kapitel 2.1.2). Detta är viktigt att ha i åtanke då fysisk störning i form av bryggor, pirar, buller, båttrafik och annat har olika påverkan på organismer som rör sig genom olika habitattyper aktivt genom migration eller passivt med strömmar. De olika spridningstyperna sker även över olika tidsskalor där aktiva migrationer ofta sker på säsongsbasis och mellan olika livsstadier, medan passiv spridning ofta sker över ett antal veckor när larver och sporer utvecklas i den fria vattenmassan innan de slår sig ner vid lämpligt habitat. Det finns även arter som genomför hela sina livscykler i den fria vattenmassan, till exempel växtplankton som också ingår som en biologisk kvalitetsfaktor att bedöma. Dessutom är det viktigt att särskilja typiska hemområden från maximala migrations- och spridningsavstånd, eftersom hemområden är relevanta för populationsdynamiken, medan de maximala migrations- och spridningsavstånden har större betydelse för den genetiska variationen mellan olika populationer. Likaså är det viktigt att ta hänsyn till hur konnektivitet kan påverkas av ett förändrat klimat. Fiskar har en central roll i de marina ekosystemen. Därför blir konnektivitet av fisk – både mellan kust och hav, inom kustområden samt mellan kust och sötvatten – avgörande faktorer för ekologisk status, både i sötvatten och i kustvatten. Eftersom det främst är fiskar som genomför vandringar mellan kust och sötvatten och kust och hav är det svårt att klassificera parametern 8.3 Konnektivitet mellan kustvatten och vatten i övergångszon och kustnära landområden i föreskrifterna (HVMFS 2019:25) utan att inkludera fisk. Fisk borde därför ingå som en biologisk kvalitetsfaktor även i föreskrifterna för kustvatten (kapitel 2.1.3). Fisk ingår vid bedömning av ekologisk status i havsmiljödirektivet, som geografiskt överlappar med vattendirektivet i kustzonen. I havsmiljödirektivet finns i stället inte konnektivitet med som ett kriterium i ekologiska statusbedömningar. Detta gör att konnektivitet, framförallt gällande fisk, inte beaktas tillräckligt i bedömningarna varför en samordning mellan direktiven måste till. Då konnektivitet främst är en biologisk funktion kopplad till fiskar och andra organismer bör det övervägas om konnektivitet ska ingå bland de biologiska kvalitetsfaktorerna istället för de hydromorfologiska.Sverige är ett av de länder inom EU som har kommit längst gällande bedömning av konnektivitet inom vattendirektivet. Övriga EU-länder tycks mer fokusera på de två andra hydromorfologiska kvalitetsfaktorerna hydrografiskt villkor och morfologiskt tillstånd i sina bedömningar. Detta kan bero på att konnektivitet inte ingår i vattendirektivet men att man i Sverige har valt att lägga in det Sammanfattning som en egen kvalitetsfaktor i föreskrifterna om statusbedömning i svenska kustvatten. Konnektivitet nämns i några sammanhang i andra EU-länder, men är då oftast kopplat till sötvatten med fokus på vandrande fiskar och hinder i form av vattenkraft och andra fysiska strukturer som stoppar vattenflödet. Intresset för att utveckla den hydromorfologiska kvalitetsfaktorn där konnektivitet ingår har vuxit inom EU och ett antal rapporter och vetenskapliga artiklar finns tillgängliga i ämnet (kapitel 2.1.4).Konnektivitet kan mätas på olika sätt och på olika rumsliga skalor. I kapitel 3 sammanfattar vi denna information i ett kunskapsunderlag för bedömning av konnektivitet i kustzonen. Mätning och analys av arters spridning i kust- och havsområden är en utmanande uppgift, och kunskapen inom detta område är fortfarande begränsad. För att analysera och bedöma aktiv migration i framförallt Östersjön och Skagerrak har rumsliga analyser baserade på habitatkartor och information om arters spridningsavstånd använts, likaså märkningsstudier och kombinationer av metoder. För att undersöka passiv spridning har man främst använt en kombination av empiriska data och hydrodynamiska modeller för att undersöka spridningsvägar och uppväxtmiljöer för olika marina organismer och för att identifiera viktiga områden för konnektivitet som till exempel källor och sänkor. I kapitel 3 sammanfattas även konnektivitetsmönster hos några biologiskt viktiga organismgrupper och information om naturliga barriärer som salthalt, djup och temperatur som påverkar spridning av organismer och organiskt material.Få studier har undersökt effekter av fysisk störning på konnektivitet. I kapitel 4.2 beskriver vi studier som gjorts i svenska vatten gällande effekter av fysisk störning på passiv spridning och aktiv migration och i kapitel 4.3 sammanfattar vi information om fysisk påverkan och konnektivitet på några nyckelhabitat. I kapitel 5 beskrivs resultaten av nya analyser med fokus på fisk längs svenska västkusten som gjorts inom ramen av detta uppdrag. Resultaten från dessa studier visar att fysisk påverkan kan ha en betydande inverkan på konnektivitet, särskilt för de arter som är beroende av grunda och vågskyddade områden för sin reproduktion. Denna typ av habitat är särskilt känslig och uppvisar en påtaglig minskning av konnektiviteten till följd av fysisk påverkan. Just dessa områden drabbas mest av förluster i konnektivitet då de har en hög grad av fysisk exploatering, inkluderande bryggor, bojar och småbåtshamnar. Dessutom visade resultaten från vår modellering att makroalger och fröväxter påverkas starkt av fysiska förändringar. Detta understryker vikten av att noggrant utvärdera och hantera fysisk påverkan på arter och livsmiljöer i kustzonen för att bevara och skydda känsliga marina ekosystem och de tjänster de tillhandahåller. Resultaten är viktiga för beslutsfattare och planerare som arbetar med bevarandeåtgärder och förvaltning av dessa miljöer.Det finns betydande kunskapsluckor inom området konnektivitet i kustvattenmiljöer och även inom området fysisk påverkan på konnektiviteten. I kapitel 6 listas dessa kunskapsluckor där bland annat behovet av högupplösta kartunderlag över förekomsten av både organismer och påverkansfaktorer pekas ut, liksom sambanden mellan dessa. Detta gäller för de biologiska kvalitetsfaktorerna bottenfauna, makroalger, fröväxter och växtplankton och för fisk, där fisken inte ingår som biologisk kvalitetsfaktor i kustzonen. Även effekter av ett förändrat klimat och av olika typer av restaureringsåtgärder på konnektiviteten är områden där det finns behov av att förbättra kunskapsläget