Seaweeds: an opportunity for wealth and sustainable livelihood for coastal communities

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.     

Seaweed production: overview of the global state of exploitation,farming and emerging research activity

ABSTRACT

The use of seaweeds has a long history, as does the cultivation of a select and relatively small group of species. This review presents several aspects of seaweed production, such as an update on the volumes of seaweeds produced globally by both extraction from natural beds and cultivation. We discuss uses, production trends and economic analysis. We also focus on what is viewed as the huge potential for growing industrial-scale volumes of seaweeds to provide sufficient, sustainable biomass to be processed into a multitude of products to benefit humankind. The biorefinery approach is proposed as a sustainable strategy to achieve this goal. There are many different technologies available to produce seaweed, but optimization and more efficient developments are still required. We conclude that there are some fundamental and very significant hurdles yet to overcome in order to achieve the potential contributions that seaweed cultivation may provide the world. There are critical aspects, such as improving the value of seaweed biomass, along with a proper consideration of the ecosystem services that seaweed farming can provide, e.g. a reduction in coastal nutrient loads. Additional considerations are environmental risks associated with climate change, pathogens, epibionts and grazers, as well as the preservation of the genetic diversity of cultivated seaweeds. Importantly, we provide an outline for future needs in the anticipation that phycologists around the world will rise to the challenge, such that the potential to be derived from seaweed biomass becomes a reality.     

The role of birds in sustainable food production

Birds (Class Aves) are already an important source of food in most parts of the world. Only a few species have been successfully domesticated but many others are harvested from the wild. There is potential for greater use of birds as a food source. Existing domesticated species, especially galliforms, need to be better utilized. Certain new species could be brought into domestication. The efficiency and sustainability of harvesting methods for free-living birds might be improved and the harvesting of new species should be considered. These measures could be compatible with improved conservation of wild birds and their habitats, but careful planning and surveillance are essential prerequisites.     

The roles and values of wild foods in agricultural systems

Almost every ecosystem has been amended so that plants and animals can be used as food, fibre, fodder, medicines, traps and weapons. Historically, wild plants and animals were sole dietary components for hunter–gatherer and forager cultures. Today, they remain key to many agricultural communities. The mean use of wild foods by agricultural and forager communities in 22 countries of Asia and Africa (36 studies) is 90–100 species per location. Aggregate country estimates can reach 300–800 species (e.g. India, Ethiopia, Kenya). The mean use of wild species is 120 per community for indigenous communities in both industrialized and developing countries. Many of these wild foods are actively managed, suggesting there is a false dichotomy around ideas of the agricultural and the wild: hunter–gatherers and foragers farm and manage their environments, and cultivators use many wild plants and animals. Yet, provision of and access to these sources of food may be declining as natural habitats come under increasing pressure from development, conservation-exclusions and agricultural expansion. Despite their value, wild foods are excluded from official statistics on economic values of natural resources. It is clear that wild plants and animals continue to form a significant proportion of the global food basket, and while a variety of social and ecological drivers are acting to reduce wild food use, their importance may be set to grow as pressures on agricultural productivity increase.     

From Reef to Table: Social and Ecological Factors Affecting Coral Reef Fisheries,Artisanal Seafood Supply Chains,and Seafood Security

Ocean and coastal ecosystems provide critical fisheries, coastal protection, and cultural benefits to communities worldwide, but these services are diminishing due to local and global threats. In response, place-based strategies involve communities and resource users in management have proliferated. Here, we present a transferable community-based approach to assess the social and ecological factors affecting resource sustainability and food security in a small-scale, coral reef fishery. Our results show that this small-scale fishery provides large-scale benefits to communities, including 7,353 ± 1547 kg yr^-1 (mean ± SE) of seafood per year, equating to >30,000 meals with an economic value of $78,432. The vast majority of the catch is used for subsistence, contributing to community food security: 58% is kept, 33.5% is given away, and 8.5% is sold. Our spatial analysis assesses the geographic distribution of community beneficiaries from the fishery (the “food shed” for the fishery), and we document that 20% of seafood procured from the fishery is used for sociocultural events that are important for social cohesion. This approach provides a method for assessing social, economic, and cultural values provided by small-scale food systems, as well as important contributions to food security, with significant implications for conservation and management. This interdisciplinary effort aims to demonstrate a transferable participatory research approach useful for resource-dependent communities as they cope with socioeconomic, cultural, and environmental change.     

53 A Seaweed's perspective on marine reserves

In response to major changes in coastal ecosystems in recent decades, a number of governmental agencies around the world are establishing marine reserves – areas where removal of animals or plants is prohibited. Although marine reserves are touted as an ecosystem based approach to management of marine resources, the vast majority of attention on reserve design and impact focuses solely on fish. Although a few species of algae are commercially harvested, most are not. As a result, they will receive little direct benefit from protection by reserves aside from habitat protection. From the perspective of a seaweed, the primary impacts of marine reserves will therefore be indirect through species interactions. We examine the rapidly growing theoretical and empirical literature on marine reserves to anticipate the likely responses of seaweeds to exclusion of fishing. The key issues that emerge are: the trophic level of prior fishing and the dispersal scales of seaweeds relative to their competitors and consumers. The latter issue is poorly understood and poses a key challenge to phycologists if we are to effectively incorporate seaweeds into future marine reserve design.     

Recent developments in manufacturing and marketing carrageenan

Carrageenan has annual sales of over US$ 200 million, about 15% of the world use of food hydrocolloids. The market for carrageenan has grown exponentially at 5% per year for at least 25 years: 5 500 metric tons in 1970, and over 20 000 metric tons expected in 1995. The industry has become dominated by very large, multi-product companies with carrageenan factories in Europe and the US, but factories are now springing up in the Philippines and Chile, where red seaweeds grow in abundance. About 80 000 tons of dry red seaweeds are needed to produce 20 000 tons of carrageenan. About 40 000 tons comes from the Philippines, 15 000 tons from Indonesia, 15 000 tons from Chile, and 10 000 tons from elsewhere. Carrageenan growth depends on food fads like the McLean hamburger and food winners like processed pork and turkey. Carrageenan is a regulated food additive, and current health concerns focus on the minimum safe molecular weight for carrageenan when eaten. The most innovative development in carrageenans in recent years has been the introduction of a food grade version of lower cost natural grade carrageenan. Its acceptance, however, has been hampered by strong resistance from conventional carrageenan producers.     

Acclimation of bloom‐forming and perennial seaweeds to elevated pCO2 conserved across levels of environmental complexity

Macroalgae contribute approximately 15% of the primary productivity in coastal marine ecosystems, fix up to 27.4 Tg of carbon per year, and provide important structural components for life in coastal waters. Despite this ecological and commercial importance, direct measurements and comparisons of the short‐term responses to elevated pCO₂ in seaweeds with different life‐history strategies are scarce. Here, we cultured several seaweed species (bloom forming/nonbloom forming/perennial/annual) in the laboratory, in tanks in an indoor mesocosm facility, and in coastal mesocosms under pCO₂ levels ranging from 400 to 2,000 μatm. We find that, across all scales of the experimental setup, ephemeral species of the genus Ulva increase their photosynthesis and growth rates in response to elevated pCO₂ the most, whereas longer‐lived perennial species show a smaller increase or a decrease. These differences in short‐term growth and photosynthesis rates are likely to give bloom‐forming green seaweeds a competitive advantage in mixed communities, and our results thus suggest that coastal seaweed assemblages in eutrophic waters may undergo an initial shift toward communities dominated by bloom‐forming, short‐lived seaweeds.     

The harvesting of macroalgae in New Zealand

Several species of algae have been commercially harvested in New Zealand, mainly for extraction of agar and alginates. In the past, the harvest was comprised mostly of shore-cast plants. There has been more recent interest, however, in harvesting attached plants of Pterocladia spp., Porphyra spp., Gracilaria sordida, Durvillaea spp., Macrocystis pyrifera, and Ecklonia radiata. The ecological effects of harvesting attached algae depend largely on the sizes of plants, the season of removal, the patch size of clearances, and the proximity and identity of mature plants. These have not been well-studied for seaweeds in New Zealand, but population and life history studies indicate that harvesting methods affect the continuity of algal resources, at least on a local scale, and are crucial factors in their management.     

Grassland harvesting alters ant community trophic structure: An isotopic study in tallgrass prairies

Disturbances have long been recognized as important forces for structuring natural communities but their effects on trophic structure are not well understood, particularly in terrestrial systems. This is in part because quantifying trophic linkages is a challenge, especially for small organisms with cryptic feeding behaviors such as insects, and often relies on conducting labor‐intensive feeding trials or extensive observations in the field. In this study, we used stable isotopes of carbon and nitrogen to examine how disturbance (annual biomass harvesting) in tallgrass prairies affected the trophic position, trophic range, and niche space of ants, a widespread grassland consumer. We hypothesized that biomass harvest would remove important food and nesting resources of insects thus affecting ant feeding relationships and trophic structure. We found shifts in the feeding relationships inferred by isotopic signatures with harvest. In particular, these shifts suggest that ants within harvest sites utilized resources at lower trophic levels (possibly plant‐based resources or herbivores), expanded trophic breadth, and occupied different niche spaces. Shifts in resource use following harvest could be due to harvest‐mediated changes in both the plant and arthropod communities that might affect the strength of competition or alter plant nitrogen availability. Because shifts in resource use alter the flow of nutrients across the food web, disturbance effects on ants could have ecosystem‐level consequences through nutrient cycling.     

Recent trends of seaweed production in Chile

In the last fourteen years the production of seaweeds in Chile has ranged from 74 000 to 229 000 wet metric tons per year and has included about twenty species belonging to Phaeophyta and Rhodophyta. The only source of this production has been the exploitation of natural beds, except for Gracilaria, which is the only case of commercial cultivation and contributes significant quantities to total production. Initially most of the raw material was exported but currently important quantities of Gracilaria and several carrageenophytes are being processed by local industry. Changes in production of the main resources are analyzed with consideration of potential demand, level of knowledge about natural beds, and the situation of total Gracilaria farming, in order to attempt predictions for the supply. Current possibilities of applying new technologies to cultivate other economically important Chilean seaweeds are also analyzed and discussed.     

The Lessonia nigrescens fishery in northern Chile: “how you harvest is more important than how much you harvest”

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.     

Trade in Palm Products in North-Western South America

More than 200 scientific publications and Internet sources dealing with trade in palm products in north-western South America are reviewed. We focus on value chains, trade volumes, prices, and recent developments for some of the most important raw materials derived from native palms. Trade in palm products takes place at local, regional, national, and international levels. For local communities and individual households palm products may play a key role as the most important or only source of cash income. Most of these palm products are inadequately or not at all captured in trade statistics at the local and regional economic levels. Only products such as vegetable ivory and palm heart are monitored statistically, mainly because they are exported. Most raw materials derived from palms are extracted from the wild, and mainly by destructive harvesting. Reduced availability and rising prices on local and regional markets reflect incipient resource depletion. Only in vegetable ivory more or less sustainable wild harvesting methods prevail. Palm heart is increasingly being harvested from orchards and non-sustainable exploitation of wild populations is loosing ground. The international market for native palm oils and pulp (esp. Euterpe oleracea or açaí) is currently served almost exclusively from Brazil. Due to low oil contents and high production costs palm oils are currently used mainly for cosmetics. Based on their content of protein, starch, tocols, and carotenoids palm fruits have high nutritional value and represent a considerable potential for the development of functional foods, food supplements and animal fodder. Palms could undoubtedly play a more important role in the socio-economic development of north-western South America. Sustainability and marketing potential of palm products are negatively affected by the low income obtained by primary producers which often represents no more than 0.01–3% of the retail value. Poor governance, insecurity of land tenure and unequal sharing of profits endanger a sustainable long-term development of these valuable resources.     

Historical context of commercial exploitation of seaweeds in Brazil

Harvested by coastal populations for centuries, seaweeds have played an important role in the economy of a number of countries. In Brazil, they occur along the coastline, but are more diversified and abundant from the northeast to a portion of the southeast coast. Historically, the seaweed industry in Brazil is based on seaweed harvesting of natural beds. This practice continues to this day in a number of coastal communities in Northeastern Brazil. Since the 1960s, species of the genera Gracilaria and Hypnea have been collected in the intertidal zone for extraction of agar and carrageenan. Maximum production was achieved in 1973–1974, a period in which the country exported around 2000 t annually (dry weight) to Japan. Later (1977–1979), there was a sharp drop and annual exports fell to 250 t (dry weight). In 1981, Brazil exported only 150 t of dried seaweed for agar extraction. Between 1990 and 2000, overexploitation, decline in a number of agarophyte populations, poor quality, low price, and lack of a socioeconomic policy led to the almost total disappearance of this industry in Northeastern Brazil. Seaweed harvesting on natural beds is currently in decline, and the population that depended on this resource had to migrate or convert to other economic activities, such as fishing, aquaculture, and underwater tourism. However, the promising results obtained in pilot projects (Gracilaria and Kappaphycus) show that Brazil has significant potential as a seaweed biomass producer.     

Using the biogeographical distribution and diversity of seaweed species to test the efficacy of marine protected areas in the warm-temperate Agulhas Marine Province, South Africa

Aim To study the siting of marine protected areas (MPAs) with respect to the biogeographical distribution of seaweeds within the Agulhas Marine Province and to assess the effectiveness of current MPAs in including (conserving) seaweeds of the South African south coast. Location South Africa – the south coast between Cape Agulhas and the Eastern Cape/Kwazulu‐Natal border, and eight MPAs within that area. Methods We used interpolated seaweed distribution records from all available sources, in 50‐km coastal sections. Cluster analysis (Jaccard Average Linkage) of species presence/absence data provided measures of similarity between coastal sections and between MPAs. Complementarity analyses identified the sequence of ‘importance’ of sections/MPAs for conserving seaweed species. Results Species presence/absence data indicated two main groups, representing western (cooler water) and eastern (warmer water) biogeographical divisions, as well as several biogeographical subdivisions within each of these groups. Complementarity analysis yielded a sequence of ‘importance’ of coastal sections (in terms of the highest number of species included) that began with a section just east of central in the Agulhas Marine Province, around Port Alfred, where there is no MPA. This was followed by the easternmost section (warmest water), which contains the Pondoland MPA, and then by the westernmost (coolest water) section, containing the De Hoop MPA. Similar analysis of the actual species collected in MPAs showed a generally similar pattern. Main conclusions Seven current MPAs and one proposed coastal MPA in the Agulhas Marine Province appear to be well distributed and well sited to include (conserve) the full biogeographical range of seaweeds. However, if further MPAs are to be considered, the Port Alfred area is recommended for improved conservation. This study did not examine estuaries, which may require improved conservation efforts. Seaweed distribution data, which are often relatively complete, offer a good tool for planning the siting of coastal MPAs.     

Sustainable Utilization and Economic Development of Some Plant Resources in Northern Pakistan

Overshadowed by the vast impact that habitat loss has on targeted plant species survival, it is easy to overlook the fact that utilization and harvesting of species can often result in their genetic depletion and in an often rapid downward trend of their population status. In this regard an ethnobotanical study on the medicinal plants of Shawar valley, District Swat was conducted with the aims to document medicinal plants and to examine the current status of the medicinal plants trade as well as the market chain starting from collectors to consumers. The survey reported 50 species of plants belonging to 33 families as ethnomedicinally important. These species were used as crud drugs by the local people and folk-lore for treating diseases in traditional system of medicine. The detailed local uses, recipe preparation along with their local names and diseases treated were recorded for each species.Market survey revealed that the structure of medicinal plant trade is complex and heterogeneous, involving many players. The collectors are often not aware of the high market prices and medicinal values, and most of the collected material is sold to local middlemen at a very low price. There was an increase of 3 to 5 folds in prices from collectors to the national market.Recommendations were given in the spheres of training sustainable harvesting and post harvesting of wild medicinal plant resources, trade monitoring, equitable sharing of benefits of wild resources, improved control on harvesting and trade for the conservation of resources, enhancement of cultivation efforts, future research into trade in wild harvested plants, community participation in natural resource management and value addition in the herbal products to maximize the benefits.     

Escalating Worldwide use of Urea – A Global Change Contributing to Coastal Eutrophication

While the global increase in the use of nitrogen-based fertilizers has been well recognized, another change in fertilizer usage has simultaneously occurred: a shift toward urea-based products. Worldwide use of urea has increased more than 100-fold in the past 4 decades and now constitutes >50% of global nitrogenous fertilizer usage. Global urea usage extends beyond agricultural applications; urea is also used extensively in animal feeds and in manufacturing processes. This change has occurred to satisfy the world’s need for food and more efficient agriculture. Long thought to be retained in soils, new data are suggestive of significant overland transport of urea to sensitive coastal waters. Urea concentrations in coastal and estuarine waters can be substantially elevated and can represent a large fraction of the total dissolved organic nitrogen pool. Urea is used as a nitrogen substrate by many coastal phytoplankton and is increasingly found to be important in the nitrogenous nutrition of some harmful algal bloom (HAB) species. The global increase from 1970 to 2000 in documented incidences of paralytic shellfish poisoning, caused by several HAB species, is similar to the global increase in urea use over the same 3 decades. The trend toward global urea use is expected to continue, with the potential for increasing pollution of sensitive coastal waters around the world.     

Regional Patterns in Global Resource Extraction

This article presents an account of global resource extraction for the year 1999 by material groups, world regions, and development status. The account is based on materials flow analysis methodology and provides benchmark information for political strategies toward sustainable resource management. It shows that currently around 50 thousand megatons of resources are extracted yearly on a global scale, which results in a yearly global average resource use of around 8 tonnes per capita. Assuming further growth in world regions not yet close to the levels of resource use in the industrial cores—such as India or China—numbers could easily double once these parts of the world come to fully incorporate the industrial mode of production and consumption. This article contributes to information on resource use indicators, complementing and enriching information from economic accounting in order to facilitate political measures toward a sustainable use of resources.     

The Long‐term Impact of Timber Harvesting on the Resource Base of Chimpanzees in Kibale National Park,Uganda

Commercial timber harvesting results in the loss of critical habitat for tropical forest fauna, and large‐bodied frugivores (including chimpanzees and most other apes) may experience particularly detrimental effects. Few quantitative data, however, are available to evaluate the long‐term impact of harvesting on chimpanzees and other apes. In particular, few data are available to compare population demographics and/or forest composition before and after timber harvesting at the same site. Utilizing detailed forestry department records of logging operations conducted in the late 1960s, present‐day botanical surveys, and long‐term data on the feeding ecology of chimpanzees in Kibale National Park (KNP), Uganda, I examined the impact that logging has had on KNP chimpanzee communities of known size and demography. Although some important chimpanzee food resources were harvested in high abundance during commercial logging operations, the overall impact on the most predominant dietary items (those making up roughly 75% of the chimpanzees' diet) and on presumably critical subsistence resources was limited. Furthermore, the low density of chimpanzees inhabiting the logged region of KNP is apparently not attributable to the impact of logging at the site: comparisons of resource densities at this ‘low‐chimpanzee‐density’ site with that of an unlogged and ‘high‐chimpanzee‐density’ KNP site did not differ when logging concessions at the low‐chimpanzee‐density site were excluded from the analysis. This study suggests that low‐intensity logging can be compatible with the conservation of large‐bodied frugivores, provided that dietary data are taken into account in forest management planning.