Kelp beds, besides being one of the most important benthic resources in northern Chile, provide a variety of environmental goods and services. In order to evaluate economically the wild kelp ...populations in northern Chile (26° to 32° S) more than simply their commercial value as a source of raw materials for alginate extraction, we used several economic indicators to holistically assess the value of a group of brown seaweeds of economic importance, Lessonia spp. and Macrocystis pyrifera: (1) market value of biomass as a source of raw material for extraction of alginic acid, (2) market value of associated species of economic importance, (3) value as a source of scientific information, (4) value as a climate buffer (CO₂ capture and release of O₂), (5) value of associated biodiversity (non-commercial species), (6) value as cultural heritage and (7) value as a reservoir of biodiversity. Existence values of kelp beds which estimate the willingness of citizens to pay and work without payment to preserve the ecosystem were calculated using the contingent valuation technique. The results indicate that kelp beds in northern Chile have a total value of US $540 million. Of this total, kelp fishery accounts for 75 % and associated-species fisheries account for 15 %. In this context, the economic value of Chilean kelp beds is mainly associated with the industry of alginate extraction. By contrast, existence value as a source of scientific information or environmental buffer for CO₂ capture or O₂ production represents only 9 % of the total value, representing a very low relative importance to society. The economic valuation of coastal resources and marine ecosystems is a complementary tool for decision making and implementation of public policies related to the conservation and sustainable exploitation of renewable resources and their ecosystems.
Chile is an important producer of brown seaweeds representing 10% of world supply. Landings of Chilean kelp fluctuated between 40,000 t.year⁻¹ in the early '80s to 250,000 t.year⁻¹ more recently. ...Commercialized algae come from natural populations and no mass-cultures of involved species have been established. Four species of brown algae are commercially collected in the country: Lessonia trabeculata, L. nigrescens, Macrocystis pyrifera and M. integrifolia. Since 2000, the demand of alginate sources and food for cultivated abalones dramatically raised the harvesting of these species. Direct evaluations of Lessonia spp. and Macrocystis standing-stocks were made along 700 km of coast in northern Chile. Lessonia spp. estimated populations exceed 900,000 t, whereas M. integrifolia does not exceed 300 t. The insights provided indicate that sustainability of Chilean kelp subjected to intense harvesting would require management programs including the following bio-ecological recommendations: (1) to harvest the entire plant including the holdfast; (2) to harvest plants larger than 20 cm in diameter; (3) to harvest plants sparsely, selecting mayor specimens; (4) rotation of harvesting areas; and (5) for Macrocystis, to cut the canopy 1-2 m from the surface. They must be implemented in a National Program of Kelp Management, elaborated by government, scientists, fisherman, and industry.
The European, Canadian, and Latin American seaweed industries rely on the sustainable harvesting of natural resources. As several countries wish to increase their activity, the harvest should be ...managed according to integrated and participatory governance regimes to ensure production within a long-term perspective. Development of regulations and directives enabling the sustainable exploitation of natural resources must therefore be brought to the national and international political agenda in order to ensure environmental, social, and economic values in the coastal areas around the world. In Europe, Portugal requires an appraisal of seaweed management plans while Norway and Canada have developed and implemented coastal management plans including well-established and sustainable exploitation of their natural seaweed resources. Whereas, in Latin America, different scenarios of seaweed exploitation can be observed; each country is however in need of long-term and ecosystem-based management plans to ensure that exploitation is sustainable. These plans are required particularly in Peru and Brazil, while Chile has succeeded in establishing a sustainable seaweed-harvesting plan for most of the economically important seaweeds. Furthermore, in both Europe and Latin America, seaweed aquaculture is at its infancy and development will have to overcome numerous challenges at different levels (i.e., technology, biology, policy). Thus, there is a need for regulations and establishment of “best practices” for seaweed harvesting, management, and cultivation. Trained human resources will also be required to provide information and education to the communities involved, to enable seaweed utilization to become a profitable business and provide better income opportunities to coastal communities.
Marine deforestation combined with growing demands from the alginate market, reliant largely on wild kelp harvesting, has heightened concern for the potential broad and cascading effects of kelp ...removal on ecosystem functioning and services. Kelps are foundation species providing key habitat and resources for other organisms, including other fished species and thus their overharvest is often anticipated to have important and complex ecological and socioeconomical consequences. However, constructing expectations and strategies as to where, when, how, or how much kelp can be safely removed is often difficult to discern from the array of individual research studies quantifying the effects of kelp removal on kelp populations and associated communities because evidence appears mixed and results could depend on kelp species, removal methods and monitoring scales. This review of observational and experimental studies aims to identify and synthesize the effects of kelp removal, their monitoring, and the trends of significant effects. Here we show that monitoring has focused mainly on kelp populations effects, and effects on the local associated algae and sessile fauna. Almost no experiment assessed spatial patterns resulting from kelp removal. Most statistically tested effects of individual studies (64.3% of total) were non-significant. From those considered statistically significant, most (60.1%) showed decreasing trends (e.g., in kelp size, abundance, reproductive potential and the abundance and diversity of some associated taxa). Long-term studies and evaluated responses to kelp removal at the relatively large spatial scales (in extent and grain size) that include the patchy mosaics of kelp forests and critically match the geographic scale over which management strategies are applied were scarce. We note that temporal and spatial monitoring scales appear limited when compared to kelp’s lifespan and dispersal potential, as well as the scale of commercial harvest areas. Thus, we seek to call attention to the need for expanding monitoring scales and metrics to better meet the knowledge required to manage kelp forests and fisheries, which becomes urgent in countries where kelp fisheries control is difficult and as the effects could be magnified by climate change.
In Chile, management of natural resources usually starts right before its imminent collapse or after evident declination. In the northern area of the country, the fishery of brown seaweeds has an ...enormous social, ecological, and economical importance. More than 11,000 people depend directly or indirectly on the collection and harvesting of this resource. Ecologically, kelps constitute areas for food, reproduction, and refuge for hundreds of invertebrates and fish species. Economically, landings up to 300,000 dry tons per year represent close to US $60 million for the industry. Until 2002, the Chilean brown seaweed fishery was mainly sustained by natural mortality, where plants cast ashore were collected by artisanal fishermen. Since then, three brown seaweed species of economic importance (Lessonia nigrescens, Lessonia trabeculata, and Macrocystis pyrifera) have been intensively harvested in coastal areas between 18° and 32° S. To manage kelp populations along the northern Chilean coast, regulations have been based on the principle “how you harvest is more important than how much you harvest”. This exploitation strategy has been adopted in consensus between fishermen, industries, governmental entities, and scientists. Since L. nigrescens represents more than 70% of total brown seaweed landings, this study tests the effects of L. nigrescens harvesting on the following population variables: (1) abundance, (2) distribution, (3) juvenile recruitment, (4) plant morphology, (5) frequency of reproductive plants, and (6) biodiversity of the macroinvertebrate community associated to kelp holdfasts. Our results show that, despite the enormous harvesting pressure on Lessonia density and biomass, the associated macroinvertebrate richness has been maintained, due to normal plant growth and high recruitment all year round.
Worldwide climate‐driven shifts in the distribution of species is of special concern when it involves habitat‐forming species. In the coastal environment, large Laminarian algae—kelps—form key ...coastal ecosystems that support complex and diverse food webs. Among kelps, Macrocystis pyrifera is the most widely distributed habitat‐forming species and provides essential ecosystem services. This study aimed to establish the main drivers of future distributional changes on a global scale and use them to predict future habitat suitability. Using species distribution models (SDM), we examined the changes in global distribution of M. pyrifera under different emission scenarios with a focus on the Southeast Pacific shores. To constrain the drivers of our simulations to the most important factors controlling kelp forest distribution across spatial scales, we explored a suite of environmental variables and validated the predictions derived from the SDMs. Minimum sea surface temperature was the single most important variable explaining the global distribution of suitable habitat for M. pyrifera. Under different climate change scenarios, we always observed a decrease of suitable habitat at low latitudes, while an increase was detected in other regions, mostly at high latitudes. Along the Southeast Pacific, we observed an upper range contraction of −17.08° S of latitude for 2090–2100 under the RCP8.5 scenario, implying a loss of habitat suitability throughout the coast of Peru and poleward to −27.83° S in Chile. Along the area of Northern Chile where a complete habitat loss is predicted by our model, natural stands are under heavy exploitation. The loss of habitat suitability will take place worldwide: Significant impacts on marine biodiversity and ecosystem functioning are likely. Furthermore, changes in habitat suitability are a harbinger of massive impacts in the socio‐ecological systems of the Southeast Pacific.
We modeled the global distribution of giant kelp, Macrocystis pyrifera, with projection under climate change scenarios. The results are sobering and provide a starting point for future modeling exercises that will be able to draw on a more comprehensive set of physical and ecological drivers that are currently unavailable to the broader community.
Northern Chile is the scenario of two main activities from a social and economic point of view the: brown seaweeds fishery and cooper mining industry. Chilean brown seaweeds of economic importance, ...commonly known as kelps, constitute a multi-specific fishery with a workforce of 15,000 people. Four species of kelps are harvested from natural populations by artisanal fishers and exported to world markets as raw material for alginate extraction. On the other hand, copper mining production, contributes 36 % of GDP and it is the major Chilean export commodity. Due to the non-existence of entry barriers to seaweed extraction, this activity has become the sink for unemployment in northern Chile mainly from mining activity. In this context, our results show that when the price of copper is in a downward cycle, it negatively affects the abundance of brown seaweeds, due to the mobility of the workforce to the coastline, increasing the illegal harvest of these marine resources. In contrast, the upward cycle of copper decreases the harvesting pressure, removing illegal harvesters from the coastline and returning them to a mining industry and its suppliers with better wages. These drivers would generate a temporary window for recovery and restoration of brown algae populations, as well as the numerous ecosystem services provided by these engineering organisms.
Abstract Background Malaria remains a global health challenge, particularly in Peru's Loreto region. Despite ongoing efforts, high infection rates and asymptomatic cases perpetuate transmission. The ...Peruvian Ministry of Health’s “Zero Malaria Plan” targets elimination. This novel study combines microscopic, molecular, and serological techniques to assess transmission intensity, identify epidemiological risk factors, and characterize species-specific patterns across villages. The findings aim to inform targeted interventions and support broader malaria elimination efforts in line with the Zero Malaria Plan initiative. Methods A cross-sectional malaria survey was conducted in the Zungarococha community, comprising the villages Llanchama (LL), Ninarumi (NI), Puerto Almendra (PA), and Zungarococha (ZG), using microscopic, molecular, and serological techniques to evaluate malaria transmission intensity. Statistical analysis, including multivariate-adjusted analysis, seroprevalence curves, and spatial clustering analysis, were performed to assess malaria prevalence, exposure, and risk factors. Results The survey revealed a high prevalence of asymptomatic infections (6% by microscopy and 18% by PCR), indicating that molecular methods are more sensitive for detecting asymptomatic infections. Seroprevalence varied significantly between villages, reflecting the heterogeneous malaria transmission dynamics. Multivariate analysis identified age, village, and limited bed net use as significant risk factors for malaria infection and species-specific exposure. Seroprevalence curves demonstrated community-specific patterns, with Llanchama and Puerto Almendra showing the highest seroconversion rates for both Plasmodium species. Conclusions The study highlights the diverse nature of malaria transmission in the Loreto region, particularly nothing the pronounced heterogeneity as transmission rates decline, especially in residual malaria scenarios. The use of molecular and serological techniques enhances the detection of current infections and past exposure, aiding in the identification of epidemiological risk factors. These findings underscore the importance of using molecular and serological tools to characterize malaria transmission patterns in low-endemic areas, which is crucial for planning and implementing targeted interventions and elimination strategies. This is particularly relevant for initiatives like the Zero Malaria Plan in the Peruvian Amazon.
Marine kelp forests cover 1/3 of our world's coastlines, are heralded as a nature-based solution to address socio-environmental issues, connect hundreds of millions of people with the ocean, and ...support a rich web of biodiversity throughout our oceans. But they are increasingly threatened with some areas reporting over 90% declines in kelp forest cover in living memory. Despite their importance and the threats they face, kelp forests are entirely absent from the international conservation dialogue. No international laws, policies, or targets focus on kelp forests and very few countries consider them in their national policy. The Kelp Forest Challenge addresses that gap. Together with 252 kelp experts, professionals, and citizens from 25 countries, the Kelp Forest Challenge was developed as a grassroots vision of what the world can achieve for kelp forest conservation. It is a global call to restore 1 million and protect 3 million hectares of kelp forests by 2040. This is a monumental challenge, that will require coordination across multiple levels of society and the mobilization of immense resources. Pledges may therefore include area for protection or restoration, enabling pledges which assist in conservation (funding, equipment, professional expertise, capacity building), or awareness-based pledges which increase awareness or education about kelp forests. Correspondingly, participants may be from government, scientific institutions, private sector, NGOs, community groups, or individuals. This challenge is the beginning of a 17-year mission to save our kelp forests and anyone and any organisation is invited to participate.
Kelp forests provide habitat and resources to diverse organisms and provide valuable ecosystem services. However, marine deforestation due to wild kelp harvesting, among other drivers, is being ...observed worldwide. Studies assessing kelp removal effects often focus on the effects on kelp populations, although deforestation also impacts the organisms that interact directly or indirectly with kelp, including herbivores and algal assemblages. Using a meta-analytical approach, we estimated the magnitude and direction of kelp removal effects on kelp, invertebrate herbivores, and understory algae. We also tested if responses varied among functional groups of understory algae and whether results were influenced by the subtidal or intertidal distribution of the removed kelp species and the time elapsed since kelp removal. We observed a substantial decrease in kelp abundance, remaining for up to 4 years following kelp removal, with a larger decrease in subtidal kelp but no recovery observed in intertidal kelp over time. Invertebrate herbivore abundance showed no significant change over time. Understory algae abundance responded positively, although this effect tended to slightly decline over time following subtidal kelp removal. Canopy-, turf-forming and foliose algae were the most benefited, which raises concern about their potential to outcompete kelp. The early succession patterns and cascading effects within kelp forests illustrated here highlight the need for long-term studies to elucidate the long-lasting effects of kelp fisheries, which are scarce at present. There is also a need to consider kelp forests’ role in providing habitat and resources to improve predictive frameworks allowing kelp forest conservation and sustainable fisheries.
•Wild kelp harvesting triggers bottom-up effects in kelp forests communities.•First meta-analyses to quantify community effects of kelp removal over time.•Opposite trends of kelp recovery following intertidal and subtidal kelp removal.•Changing effects on understory algae abundance were observed over time.•Multi-trophic and long-term effects of kelp removal need to be further studied.
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