The Falkland Islands, situated in the temperate and sub-polar South Atlantic, comprises two main islands (East and West Falkland) and 776 smaller surrounding islands (Fig. 1). This archipelago is relatively sparsely populated (2020 population = 3,480 or ~ 0.28 individuals km^-2) and is isolated geographically. The region is consequently relatively un-impacted by global human pressures (Jones et al. 2018).

Figure 1.  

Mapped distribution of kelp forest (Macrocystis pyrifera) across the Falkland Islands, based on habitat modelling undertaken in 2019 (Golding et al. 2019). Site location points of annual benthic surveys of kelp, conducted between 2008 and 2016 are shown (projection: WGS84 UTM zone 21S).

The Falkland Islands is one of the UK’s 14 overseas territories (UKOTs). As such, if they choose to have the UK’s ratification of the Paris Agreement extended to them along with other UKOTs, they will be included in the UK’s future accounting and reporting on emissions under the UN Framework Convention on Climate Change (UNFCC 2015).

The surrounding marine area covers 463,897 km² within the Exclusive Economic Zone, and includes both shallow and deep sea regions. The waters and coasts are home to a diverse mix of species (Otley et al. 2008) and extensive globally-significant Macrocystis pyrifera kelp forest habitat (Beaton et al. 2020). There is also a managed multi-species squid and finfish fishery which has been in place since 1987 and contributes to ~ 40% of Gross Domestic Product.

Current kelp distribution was mapped using image classifications based on Sentinel 1 (band 1) and Sentinel 2 (all 10 m bands) satellite imagery; Shuttle Radar Topography Mission (SRTM) data; and Landsat 8, (band 1) inputs within Google Earth Engine (Golding et al. 2019).

All satellite imagery was clipped to the Falkland Island area of interest and a cosine terrain correction was applied to the Sentinel 2 imagery to balance the effects of shadowing and bright surfaces. Cloud masking was also applied. Normalised Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), Normalised Difference Water Index (NDWI), and Geary’s C on Landsat 8’s band 1 (coastal aerosol) were calculated as further metrics for input into the model classifier. Ground-truthing points from in-water survey were additionally included for training and validation of habitat classifiers for Random Forest analysis. For further details on the broad-scale mapping methodology, see Golding et al. (2019).

Accurate satellite data for the distribution of Lessonia spp. species was not possible with this method, due to the high amount of data processing artefacts created and concealment within the larger giant kelp-dominated forest. We therefore assumed the same extent for all kelp species. Lessonia spp. can, however, be found outside the range of M. pyrifera, and M. pyrifera can live at depths of ~ 50 m+ and be non-surface touching (Graham et al. 2007). Both species’ full vertical (depth) and lateral distribution is therefore likely to be underestimated.

Kelp density

Kelp density was calculated based on field survey data collected from across the Falkland Islands between 2008 and 2016 (Shallow Marine Surveys Group, unpublished data), with a total of 315 surveys conducted between 2008 and 2016 (Fig. 1). Density values for Macrocystis pyrifera and Lessonia spp. were based on the number of individual giant kelp thali observed in-situ one metre either side along a 20 m transect (i.e 40 m² total sample area), placed randomly on the seabed within the kelp forest rocky habitat. Density (thali/m²) for each species was averaged for autumn (March – May) and spring (September – November) surveys to account for any seasonal changes in density as the forest grows and senesces. Kelp health values are assumed to be homogenous throughout the extent of mapped kelp. Due to the remoteness of these islands (Jones et al. 2018), any such differences would be solely biophysically driven (i.e. through wave exposure).

Biomass and carbon content estimation

Macrocystis pyrifera thalli mean wet weight (excluding bare stipes) was calculated using values from van Tussenbroek (1993) for spring and autumn and multiplied by the mean kelp density observed from surveys conducted during the same season (Table 1). We use the estimated current biomass of kelp to equate stored carbon in standing kelp stock, rather than daily rates of productivity per species (C m^-2 day^-1) as used in other studies (Vásquez et al. 2014). This is because turnover of standing biomass is rapid and the total storage value using daily productivity modelled over a multi-year period would likely be an overestimate of total carbon. The mean weight of carbon per metre squared was multiplied by the calculated extent of Macrocystis pyrifera within the Falkland Islands to give a total carbon standing stock, then converted to CO₂ using a conversion factor of 3.67 (based on relative atomic weights).

Kelp sequestration rate

The average net primary productivity (NPP) of Macrocystis pyrifera kelp forest (including understorey species), is estimated to be in the range 670 – 1300 g C m^-2 yr^-1, with a mean productivity value of 985 g C m^-2 yr^-1 (Reed and Bzezinski 2009). Following a global analysis by Krause-Jensen and Duarte (2016), sequestration through burial of Particulate Organic Carbon (POC) in deep waters is estimated as ~ 0.92% of annual NPP; sequestration through export of POC to the deep sea is ~ 2.30% of NPP; and sequestration through export of Dissolved Organic Carbon (DOC) is ~ 7.69% of NPP (Fig. 2). Sequestration pathway proportions were then multiplied across the current known extent of kelp forest within the Falkland Islands and converted to CO₂ equivalent (CO₂e) weight. For macro-algae growing within shallow soft sediments, approximately 0.4% of annual NPP is also buried, with the carbon sequestered to this substrate (Krause-Jensen and Duarte 2016). However, in the context of the Falkland Islands, where kelp primarily grows on hard bedrock, this shelf-burial process is less likely and is excluded from calculations.

Figure 2.  

Diagrams of: A) a typical giant kelp (Macrocystis pyrifera) thallus, illustrating the major components of the adult sporophyte plant life-stage; B) a typical giant kelp forest community structure, including kelp understorey and associated biodiversity; and C) sequestration routes of kelp forest net primary productivity (NPP) biomass to the deep sea through dissolved and particulate organic carbon (DOC/POC) pathways – based on Krause-Jensen and Duarte (2016).

Carbon value

The United Kingdom has now shifted from the direct use of the Social Cost of Carbon (SCC), which estimates lifetime damage costs of carbon to society, to a ‘target-consistent’ approach, based on emissions targets for future climate scenarios and the cost of abatement (BEIS 2019). Following this change, we use the current proposed high-series non-traded price of carbon for this study, set at £103.918 tonne^-1 CO₂e. We use the high series non-traded (i.e. all emissions outside the remit of the EU ETS sectors of power stations/industrial plants and EU airlines) values of carbon as the values were initially proposed in 2009 (DECC 2009). Since this period, international emissions targets have become more ambitious, aiming to limit global temperature change to below 2^oC above pre-industrial levels (UNFCC 2015). Additionally, projected vs. real fuel pricing has changed, there has been insufficient action to meet previous abatement targets, and alternative energy technologies have reduced in cost. This means the central carbon cost series are likely under-costing the current central values (DECC 2009, BEIS 2019).

CO₂e cost values were applied to current estimates of carbon content and sequestration potential within the Falkland Islands (based on current density and distribution and assuming no future decline in kelp extent or density). It is important to note that the current value of the carbon already sequestered to the deep sea was not estimated due to lack of data, but is likely substantial.

Our valuation is based on the replacement cost needed to recreate the function of coastal nitrogen and phosphorus regulation and recycling back to the land, if this natural service did not exist (Costanza et al. 1998). We use the cost value of $28,916 USD ha^-1 year^-1 stated by Costanza et al. (2014). The total extent over which this service value applies to for the Falkland Islands was again based on satellite estimates of the total area (hectares) of the kelp forest (Golding et al. 2019). This service value estimate will again be an underestimate of the total Falkland Islands resource, as it is based only on giant kelp which is visible on the surface of the water and not Lessonia spp. or deeper-water forest cover. The value per hectare also likely has a high range of uncertainty given the limited number of surveys on which the original replacement cost was based (Costanza et al. 1998).

We calculated average total fish catch (tonnes) over three years (2015-2017) for all 15 commercially-exploited fisheries within the Falkland Islands, based on government data (Falkland Islands Government 2018). We then selected the fisheries which are known to spawn, feed, or be resident during any part of their life-cycle within giant kelp habitats in the Falkland Islands. Limited data is available on trophic links, population distribution, ontogenetic habitat use, and life-history traits for many of these species. We therefore assume that any kelp habitat or near-kelp habitat utilisation of this type at any life-cycle stage is essential for sustaining the whole commercial fishery’s population. Similarly, we only include fisheries directly observed within the kelp, excluding the other fisheries which may be found to have indirect trophic links and bio-physical influences from kelp systems.

We use the market value of each species (£GBP/metric tonne) to estimate the total value of the kelp system in terms of exploited kelp-associated fish harvest (Falkland Islands Government 2018). Values for embedded costs of running the fishery, such as salaries, fuel and equipment needs were unknown for these fisheries, preventing a ‘value-added assessment' (i.e. revenue minus intermediate costs). Government revenue from fishery licence fees for all fisheries associated with the kelp system were averaged over a three-year period. For licences A, G and W (Suppl. material 1B), which are a mixture of restricted and unrestricted finfish, the licence fees are summarised for the nine relevant target species. Therefore the percentage of each category made up of each target species in 2017 landings was multiplied by the total licence income (Suppl. material 1C).

We use a non-use valuation technique, based on a historic alginate extraction pilot project in the Falkland Islands. A test plant was established in the 1970s (Shackleton 1976) and an economic study in the 1980s proposed obtaining a licence to harvest kelp at a minimum annual wet tonnage of 350,000 tonnes. World economic recession, global competition, and a shift of textile manufacturing to low-income countries, had caused the collapse of the textile market for alginates at that time for the UK (Shackleton 1982). We use this historic theoretical production level to contextualise the likely income from this resource if it were to be utilised in the Falkland Islands currently.

As no export industry currently exists, and given the proximity of the Falkland Islands to Chile, we assume the same export value per dry tonne for harvested kelps. Average export price of dry Lessonia spp. kelp out of Chile in 2009 for the alginate industry was US$ 950 per tonne (Bixler and Porse 2011). This equates to £917 per tonne, accounting for inflation and currency conversion to the present year.

Overall values of Macrocystis pyrifera density were highly variable, ranging between ~ 0.02 and 2.75 thalli/m² across all surveys, with a mean value of 0.293 thalli/m² (SE = ± 0.051) in spring, averaged across all years. Autumn density values were similar at 0.249 thalli/m² (SE = ± 0.039) averaged across all years. Overall values of Lessonia spp. density were again highly variable, ranging between 0.025 and 4.4 thali (whole plants)/m² across all surveys, with a mean value of 0.642 thalli/m² (SE = ± 0.069) in spring, averaged across all years. Autumn density values were 0.716 thalli/m² (SE = ± 0.082) averaged across all years.

The above seasonal density values resulted in an average of 0.12 million tonnes of CO₂e estimated to be stored in standing M. pyrifera vegetation, with a spring peak density equivalent to 0.21 million tonnes CO₂e. The average overall CO₂ stored by Lessonia spp. in the Falkland Islands is 0.30 million tonnes of CO₂e in spring and 0.37 million tonnes of CO₂e in autumn, assuming an equal proportion of L. flavicans and L. trabeculata within all surveys. Total seasonal CO₂e stored by standing kelp plants across the Falkland Islands (within the aerially-mapped extent) and respective biomass values are shown in Table 1.

Applying the mean productivity value of 985 g C m^-2 yr^-1 (Reed and Bzezinski 2009), and the estimated percentage of DOC and POC sequestered to deep sea (Krause-Jensen and Duarte 2016), the average carbon sequestration value for the Falkland Islands is 0.081 Tg carbon year^-1. This is equivalent to 0.299 million tonnes of CO­₂, as shown (with corresponding maximum and minimum estimates) in Table 2.

The combined total peak estimate of CO₂ equivalent carbon stored in standing giant and understorey kelp species within the satellite-derived mapped extent of kelp forest in the Falkland Islands is 0.58 million tonnes. Averaged (central estimate) total sequestration to the deep sea is 0.299 million tonnes of CO­₂ annually. Based on non-traded high-series carbon dioxide equivalent (CO₂e) values (BEIS 2019), of £103.9 per tonne CO₂e, present-day standing stock of carbon stored in Macrocystis and Lessonia kelp is equivalent to £60.27 million. The annual value of carbon sequestered to deep sea sediments is estimated to be approximately £31.07 million per year.

Coastal algae and seagrass beds were collectively estimated by Costanza et al. (2014) to contribute $28,916 USD per hectare per year in terms of nutrient cycling services alone as of 2011 (based on the 2007 USD purchasing power parity). Applying these global values, the Falkland Islands are likely to contribute a total of £2.4 billion per year, based on remote-sensed kelp distribution (Table 3).

Six of the 15 major fisheries within the Falkland Islands were found to be reliant on kelp for some period of their life-cycle, based on current knowledge. This includes the kingclip (Genypterus blacodes), Patagonian scallop (Zygochlamys patagonica), Patagonian squid (Doryteuthis gahi), Red cod (Salilota australis), Rock cod (Patagonotothen spp.), and Southern blue whiting (Micromesistius australis). Collectively, these fisheries total an annual harvest value of £129,291,813 (~ 24% of the total commercial fishery harvest value), and £7,049,575 in licence fees (equivalent to ~ 36% of the total licence revenue) for the Falkland Islands (Table 4).

It is important to highlight that while kelp provides habitat directly to these species, the biological and oceanographic influence of kelp to the nearshore environment will also trigger potentially large indirect effects on a range of other species, through trophic links which we are unable to assess fully here.

Based on the Shackleton (1982) theoretical estimates of the Falkland Islands’ viable annual wet tonnage extraction of 350,000 tonnes (i.e. ~ 5% of the Falkland Islands’ kelp area impacted), the total dry weight of kelp for export would be approximately 70,000 tonnes, (assuming Lessonia spp. dry weight as 20% of wet weight). Applying the Chilean export value of £917 tonne^-1 would lead to a (non-use) revenue value of £64.19 million year^-1. In the initial Shackleton (1982) economic assessment, Falkland Islands Government (FIG) would receive licence royalties, which would be equivalent to ~ £147,057 year^-1 in present value after inflation.

Table 5 displays a summary of annual and spatial value estimates for all services investigated during this study. Values for other services including tourism, scientific research, culture, and coastal protection are still currently unknown or data-limited in this region, and are therefore not included within the summary.

Carbon storage

In terms of the climate buffering benefit from carbon capture, the study showed that the Falkland Islands likely sequesters 0.299 million tonnes of CO₂ annually (at a conservative minimum estimate). This amount represents an additional annual contribution of approximately 0.1% of current UK net emissions (364.1 million tonnes CO₂e/year in 2018) towards their Nationally Determined Contribution (NDC) legally committed to through the Paris Agreement. UK’s current NDC commitment is a reduction of 61% from 1990 baseline levels of ~ 601 million tonnes CO₂e per year, by 2030 (www.gov.uk). While the contribution from Falkland Islands kelp is relatively small, this is a year-on-year national-scale positive benefit from simply maintaining the natural habitat at its current extent and condition, even applying our conservative estimates.

This element of the study would benefit from additional research in a number of areas. Firstly, it is important to have long-term data on the annual variation in the extent of kelp forests around the Falkland Islands to quantify trends in abundance and distribution (and the rate of change). More detailed analyses and predictions on depth and density/condition (health) of the kelp would also allow for improved estimates of total biomass and management. This study assumes a consistent density across the distribution and uses known biomass estimates from kelp collected at ~ 5 m only (van Tussenbroek 1993). It is therefore very likely that total biomass estimates are underestimated. Linked to this point, improved knowledge of individual species’ average biomass by height, and Falkland Islands-specific total NPP values for kelp forest would help refine future analyses (Filbee-Dexter and Wernberg 2020).

Secondly, while smaller kelps such as Lessonia spp. were included in this analysis, their full extent is actually larger than that of Macrocystis pyrifera. Lessonia spp. exist in additional locations and at a range of depths. Improving our confidence in the full extent of Lessonia spp., along with the vertical extent of deeper-water kelps from all species (which are not visible from above the water), would improve management and likely increase the overall valuation amount significantly. Increased confidence in total distribution around the Falkland Islands, especially in deep waters, could potentially be achieved through collection of acoustic backscatter data to identify presence of vegetation (Kenny et al. 2003). Combining such data with in-water benthic surveys to allow species distribution modelling (Elith and Leathwick 2009) would also improve valuation estimates. Remote-sensed satellite data on wave exposure (i.e. from Sentinel-1 Radar), would further help to parametrise modelling, and allow informed predictions to be made of coastal protection services from kelp.

Thirdly, a missing element to this valuation study is in the quantification of the amount of carbon already sequestered to the deep sea sediments from the kelp forests over the last centuries. Given current estimates of sequestration rates, this value is likely to be substantial, which should be a consideration of any future deep-sea fishing/extraction/damaging activities in these deep highly-sedimented areas. It is also worth considering the potentially significant additional carbon added to the sequestration pathway through degraded phytoplankton, waste, and carbon immobilised within dead consumer’s tissues (Bax et al. 2020), which we were unable to quantify within this study.

It is important to note that carbon valuation elements, such as the ‘Social Cost of Carbon’ (SCC) method used to create aspects of the non-market value, is essentially a construct that we as people have applied. Therefore, SCC incorporates a large amount of uncertainty, ethical judgements, political beliefs and regional variation. While SCC is very useful as a tool for conceptualising value and debating cost-benefits of a service for policy-making, it is not an absolute value, and so values will likely change over time as knowledge and perceptions change. Aligned with the variation in possible SCC values, other values which feed into the overall valuation of the carbon market, including the cost of oil, are also variable and are liable to become rapidly outdated.

Fisheries harvest

Licence fees from fisheries which are associated with the kelp forest systems amount to an average annual revenue of £7,049,575 to the Falkland Island Government or £8,493 km^-2 of kelp. Within our study, we have only evaluated the harvested commercial catch. Consequently, this estimate of the ecosystem provisioning service does not account for additional non-commercial or unharvested fish which are dependent on the system (which may sustain charismatic tourist-friendly species such as dolphins, penguins or sea lions). The harvest value is also changeable, based on market prices and catch quotas, and different fishery species may become commercially valuable in the future.

Data were limited on the proportion of the population of each fishery that is dependent on the kelp forests, and on the extent to which this habitat’s presence and health will influence the continuation of the fishery. We assume here that, if any aspect of the fisheries’ life-cycle is associated with or influenced by the kelp forest, the fishery is wholly reliant on the habitat, which may not be the case. Furthermore, we have limited information on the complete influence of the kelp inshore environment on surrounding adult or planktonic species, or a complete understanding of the likely complex trophic links which exist. Therefore, more fisheries may be indirectly linked to kelp and this is an area in need of further research.

Nutrient cycling

The greatest individual ecosystem service value comes from kelp’s ability to recycle nutrients and clean coastal waters. Without appropriate management of kelp forest systems, this service may become degraded, lowering the overall water quality surrounding the coasts and reducing productivity in associated fisheries that utilise these nutrients (Bertocci et al. 2015, Beaton et al. 2020, Jiang et al. 2020, Pfister et al. 2019). The replacement cost of this regulation service through artificial processes would be extremely costly and inefficient. The reduction in water quality through increased turbulence and phytoplankton without kelp (Narayan et al. 2016, Gaylord et al. 2007, Pfister et al. 2019) and associated loss of biodiversity and function linked to kelp forest (Graham et al. 2007), would also likely have negative impacts for the tourism value of this area, through reduced underwater and beach aesthetics (González and Holtmann-Ahumada 2017).

Kelp harvest

If the hypothetical alginate industry were to be instigated in the Falkland Islands, an appropriate management strategy and impact evaluation would be necessary in order to harvest kelp sustainably. This would need to include research into the least damaging harvest times, the extent of impact it would cause, and the optimal method of extraction. Linked to any such work would be a cost-benefit analysis of how this activity would affect the other services shown in this work and the important associated biodiversity. Additionally, in a similar fashion to carbon market values, the market values of harvested kelp-associated fish and kelp itself for the alginate industry, can also rapidly change. This is demonstrated well in the 171% increase in the export value of Lessonia-derived alginate from 1999 to 2009 (Bixler and Porse 2011).

Marine systems often hold important cultural, historical or religious values for people which live close to them and rely on their services for their livelihoods or well-being (Rodrigues Garcia et al. 2017, Martin et al. 2016). However, these services are complex to quantify in terms of monetary value and rely heavily on qualitative opinions of those people who directly interact with the coast or ocean, resulting in very limited current global information about coastal and marine cultural ecosystem services (Martin et al. 2016). There is currently a poor understanding of socio-ecological relationships in marine systems generally, limited indicators, and differing values which people assign to various systems worldwide. It is also notoriously hard to quantify and assign a monetary value to a particular habitat or location (Blake et al. 2017). Quantifying the value gained through the specific cultural services of the kelp system during this assessment was beyond the scope of the present study. However, these services are likely to be highly valuable per capita in the Falklands where the economy is largely based on a healthy marine ecosystem, and given existing broader-scale value assessments in the region (Bormpoudakis et al. 2019, Smith 2019). This difficulty in giving a monetary value for the cultural/spiritual services of ecosystems specifically, is perhaps rooted in our inability to quantify something that may in all regards be ‘priceless’ to many people. Added to this is the innate difficulty in trying to value any ecosystem in isolation from its surrounding ecosystems and the interacting species and processes, to which it is inextricably linked.

In a similar fashion to cultural services, nature-based tourism can bring significant revenue for coastal communities through visitor’s appreciation of an area’s beauty, history or recreation, alongside the associated hospitality businesses. Coral reefs, for instance, are thought to provide a value of nearly US$36 billion, or over 9% of all coastal tourism value in the world's coral reef countries (Spalding et al. 2017). Limited work has been done on the direct tourism value of kelp systems; however, locations with large kelp systems and existing tourism infrastructure, such as California and South Africa’s Cape, receive revenue because of this system, through divers and snorkellers, wildlife observers (i.e. whale or otter watching), and recreational sailors (Blamey and Bolton 2018, Loomis 2006, Viana et al. 2017). Valuations may also extend to restaurants, shops, and accommodation supporting these areas, but the values will vary considerably depending on the country, accessibility, and popularity of the location. Tourism in the Falklands (focused on wildlife viewing and historic sites) is valuable, with 57,496 cruise visitors and 1,884 land-based leisure tourists during 2017/18. While many of the species which are a focus of wildlife viewing tours depend on the kelp for their continued abundance, it is difficult to disaggregate reasons for tourist visits to one feature. Bearing this in mind and given the limited existing dive infrastructure, limited data, and remote nature of the Falkland Islands, we did not include this service in our analysis.

The coastal protection provided by natural systems such as coral reefs, mangroves, and seagrass is substantial, reducing wave heights by up to 71% and attenuating water flow (Narayan et al. 2016, Martínez et al. 2007). Valuation of the benefits of these systems is typically based on matching the equivalent costs of building man-made barriers and defences which would perform the same role. Or alternatively through the avoided costs of damage and repair to property, infrastructure or life, from coastal erosion, storm waves, or coastal flooding/saltwater-intrusion to crops or groundwater etc. (Barbier et al. 2011, Narayan et al. 2016). Dependent on the degree of infrastructure in place close to the coast, the population size, frequency/intensity of storms, and the economic wealth of the country affected, the monetary benefit of having natural systems buffering the weather can be substantial. However, again the very low population size (3,398 people) and low density (0.28 people km^-2) of the Falkland Islands, based on the 2016 census, means that the only two hubs of population and infrastructure are in the naturally sheltered capital of Stanley and the inland RAF military base. The majority of the population lives in these two locations, with the remainder spread widely around the archipelago in remote farm small-holdings. Additionally, while there has been some baseline work on local wave exposure, data are currently unavailable for all of the Falkland Islands. These factors mean that the monetary value of the extensive surrounding kelp forests in terms of storm damage mitigation is not yet possible to quantify and will likely be low/negligible for this remote island case study.

Finally, as kelp is a foundation species and ecosystem engineer, the ecological and functional role of this habitat and the species which rely on it has been the focus of much scientific research and monitoring. The habitat therefore has value in terms of creation of research grants, associated travel and subsistence expenses within local businesses, and broader value for society through the creation of knowledge. In the northern region of neighbouring Chile, the estimated annual investment, in terms of scientific and applied research, in their kelp systems was US $66,174 annually or US $25,957,253 projected over 10 years (Vásquez et al. 2014). The Falkland Islands are smaller and more geographically isolated; however, the kelp systems still attract researchers from across the world and contribute to the overall research agendas of multiple Falklands-based science organisations, such as the South Atlantic Environment Research Institute (SAERI), Falkland Islands Government, Falklands Conservation, and British Antarctic Survey. The kelp forests have also attracted visits by researchers from universities, institutes and museums across the world; including from the UK, USA, Chile, Portugal and New Zealand during the last 10 years alone. However, detailed data quantifying research grants and expenses relating specifically to kelp research were limited, again preventing the inclusion of this service within our present analysis.

The Falkland Islands’ kelp system appears to be healthy and stable based on the data currently available. However, a great deal of uncertainty still exists over how this and other kelp habitats globally will fare into the future (Smale et al. 2013, Sutherland et al. 2020). In the ‘state of the environment’ and Biodiversity Framework reports produced by Falkland Islands Government (FIG Environmental Planning Department 2016, Otley et al. 2008), a number of risk factors are identified for kelp, which need to be appropriately managed to avoid any degradation (and subsequent loss of value) of this system. As is typical of many small island nations, high priority threats are from potential invasive species and biosecurity issues. Medium and low threats come from development (i.e. habitat conversion) in coastal regions, pollution, and potential oil spills from exploration and extraction in the region. Any unregulated fishing activities, potential increases in land-based nutrient flows from farming practices, and the potentially damaging effects of tourism also need to be managed. Overarching all of these threats are the potential direct and indirect effects associated with future climatic change (Krumhansl et al. 2016, Smale et al. 2019).

While the majority of the local threats can be managed, uncertainty associated with broader climate-induced impacts on kelp and its associated communities, is likely to be the highest concern over the coming years (Krumhansl et al. 2016, Peters et al. 2019). Kelp is, to some degree, resilient to acute temperature fluctuations (Reed et al. 2016). Depite this resilience, increases in storm occurrence, chronic temperature changes, and shifting of key associated species’ range will all drive potentially detrimental changes to this habitat (Krumhansl et al. 2016, Pecl et al. 2017, Arafeh-Dalmau et al. 2019). Such environmental changes would most likely reduce both the total habitat extent and the habitat quality, thereby reducing the kelp's ability to sequester carbon, cycle nutrients and provide habitat around the Falkland Islands. Just as on the land, the appropriate management and assessment of the carbon currently held within marine systems and their ability to sequester more, is an important component of mitigating climate change through reduction of emissions. Over the short-term, to maintain ecosystem service benefits and limit localised threats, sustained local management and monitoring of condition are needed (Macreadie et al. 2017b, Krumhansl et al. 2016). Furthermore, adaptations of existing management frameworks similar to the UN REDD+ (Reducing Emissions from Deforestation and forest Degradation) scheme for terrestrial forests might usefully be applied. Good marine and coastal management in this form will serve to protect not only the services directly utilised by humans, but also the important and abundant associated biodiversity supported by the kelp systems (Beaton et al. 2020, Duarte et al. 2020, Filbee-Dexter 2020).

While not directly valued in this study, biodiversity plays a key role in providing the basis of many ecosystem services. Large healthy systems which are highly biodiverse can therefore improve the value of services and the systems are more likely to be sustainable (Isbell et al. 2015). Kelp forest provides habitat both on the benthic floor and throughout the water column to a host of associated species, ranging from small invertebrates to large cetaceans (Beaton et al. 2020, Graham et al. 2007). More broadly, drifting kelp can provide important trophic and nutrient subsidies to beach communities (Lowman et al. 2019), as well as aid dispersal of sessile benthic fauna (Nikula et al. 2010). Kelp forest and its associated species therefore play important ecological roles for sustaining commercially-valuable species, as well as providing trophic pathways for a range of functional nearshore processes (Smale et al. 2013, Steneck et al. 2002). Aside from these direct values, diverse ecosystems are potentially important for humanity through the development of chemicals and medicines, and hold an inherent existence/bequest value to future generations (Smale et al. 2013, Filbee-Dexter 2020). While these functions and values can be extremely difficult to quantify monetarily, the continued maintenance and health of these systems and their associated species is an important factor to consider when judging ecosystem services and how to manage these into the future (Sanchirico and Mumby 2009, Nash et al. 2017).