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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.

Territorial use rights in fisheries (TURF) are considered to aid to the sustainability of small-scale fisheries, because they remove the perverse incentives, which sustain the tragedy of the commons. Nevertheless, a comprehensive evaluation of the implementation of TURFs is lacking. Chile offers a unique opportunity, because an extensive system for benthic fisheries has been implemented, with at present hundreds of TURFs along the coast. This study analyzes the sustainability of all the TURFs (109) along a stretch of 800 Km of coast, using population, productive, economic, social and institutional indicators. The information was obtained from the technical reports and monitoring each TURF has to prepare for the authority each year, databases the authority has and interviews with artisanal fishermen. Three states of TURFs were identified: unsustainable, poorly sustainable and sustainable. The resources exploited in the analyzed TURFs are the chilean abalon or “loco” (Concholepas concholepas), the key hole limpets “lapa negra” (Fissurella latimarginata), and “lapa rosada” (Fissurella cumingi), the kelps “huiro negro” (Lessonia berteroana), and “huiro palo” (Lessonia trabeculata), the surf clam “Macha” (Mesodesma donacium), the scallop “ostión del norte” (Argopecten purpuratus) and the seaurchin “erizo rojo” (Loxechinus albus). Results show general low performance for population, production and economic indicators, but good performance for social and institutional indicators. Overall the system shows a poor sustainability, which principally means unstable populations, landings and income in most of the TURFs. This result, which differs from most published analyses of the system, is explained mainly by the impossibility to reach a stable fishery through management of so small areas, given the natural variability of the species and the general environment. The good performance of some TURFs cannot be explained by a single factor, which is consistent with the complexity of the system, which makes it little amenable for proper management.

In Chile, a Territorial User Rights for Fisheries system was developed to manage benthic fisheries. This system is referred to as Management Areas for the Exploitation of Benthic Resources. Management areas involved a shift from top-down control by governments to comanagement. We have analyzed the effects of a highly variable fishery, characterized by boom-and-bust cycles, on the governance of local institutions designed for resource management. We focused on a case study in north central Chile, in which the surf clam fishery experienced high levels of variability when the fishery was in an open access system. The management areas were established for the fishery in 1999. As a result, a set of rules for the fishery were created and enforced by fishers and local fishery authorities. Despite intense efforts on the part of all stakeholders, the fishery collapsed after three years of management area policy. This approach has been shown to be an effective management option for other species; however, for resources with boom-and-bust cycles, it is important to understand the response pattern of users confronting this spatial and temporal variability before the establishment of territorial user rights. Defining the appropriate spatial scale of the territorial rights could allow fishers to switch among different surf clam beds to maintain their livelihood and support the sustainability of local institutions for resource management.

Consumer pressure in benthic communities is predicted to be higher at low than at high latitudes, but support for this pattern has been ambiguous, especially for herbivory. To understand large-scale variation in biotic interactions, we quantify consumption (predation and herbivory) along 2500 km of the Chilean coast (19°S–42°S). We deployed tethering assays at ten sites with three different baits: the crab Petrolisthes laevigatus as living prey for predators, dried squid as dead prey for predators/scavengers, and the kelp Lessonia spp. for herbivores. Underwater videos were used to characterize the consumer community and identify those species consuming baits. The species composition of consumers, frequency of occurrence, and maximum abundance (MaxN) of crustaceans and the blenniid fish Scartichthys spp. varied across sites. Consumption of P. laevigatus and kelp did not vary with latitude, while squid baits were consumed more quickly at mid and high latitudes. This is likely explained by the increased occurrence of predatory crabs, which was positively correlated with consumption of squidpops after 2 h. Crabs, rather than fish, were the principal consumers of squid baits (91% of all recorded predation events) at sites south of 30°S. Fish and crustaceans preyed in similar proportion on P. laevigatus, with most fish predation events at northern sites. The absence of any strong latitudinal patterns in consumption rate of tethered prey is likely due to redundancy among consumers across the latitudinal range, with crustaceans gaining in importance with increasing latitude, possibly replacing fish as key predators.

Kelp forests are declining in many parts of the globe, which can lead to the spreading of barren grounds. Increased abundances of grazers, mainly due to reduction of their predators, are among the causes of this development. Here, we compared the species richness (SR), frequency of occurrence (FO), and maximum abundance (MaxN) of predatory fish and their predation pressure between kelp forest and barren ground habitats of northern-central Chile. Sampling was done using baited underwater cameras with vertical and horizontal orientation. Two prey organisms were used as tethered baits, the black sea urchin Tetrapygus niger and the porcelanid crab Petrolisthes laevigatus . SR did not show major differences between habitats, while FO and MaxN were higher on barren grounds in vertical videos, with no major differences between habitats in horizontal videos. Predation pressure did not differ between habitats, but after 24 h consumption of porcelanid crabs was significantly higher than that of sea urchins. Scartichthys viridis/gigas was the main predator, accounting for 82% of the observed predation events on Petrolisthes laevigatus . Most of these attacks occurred on barren grounds. Scartichthys viridis/gigas was the only fish observed attacking (but not consuming) tethered sea urchins. High abundances of opportunistic predators ( Scartichthys viridis/gigas ) are probably related to low abundances of large predatory fishes. These results suggest that intense fishing activity on large predators, and their resulting low abundances, could result in low predation pressure on sea urchins, thereby contributing to the increase of T. niger abundances in subtidal rocky habitats.

Divers have widely participated in citizen science (CS) projects and are one of the main groups of marine citizen scientists. However, there is little knowledge about profiles of, and incentives for potential divers to join CS projects. To date, most studies have focused on SCUBA diving industry; nevertheless, there is a diversity of divers, not all using SCUBA, who engage in different activities during their dives. Differences in diver profiles could affect their willingness and ability to contribute to CS. In this study, we compare the diving profile, interests, preferences and motivations to participate in CS of five diver types (artisanal fishermen, recreational divers, instructors, scientific divers, and others). All divers have strong interests in participating in CS projects, with no major differences among diver types. In general, they are interested in a wide variety of themes related to CS but they prefer simple sampling protocols. Divers are motivated to participate in CS to learn about the sea and contribute to science. Some important differences among diver types were found, with artisanal fishermen having significantly more dive experience than other diver types, but less free time during their dives and limited access to some communication channels and technologies. These characteristics make them ideal partners to contribute their local ecological knowledge (LEK) to local CS projects. In contrast, recreational divers have the least experience but most free time during their dives and good access to cameras and communications channels, making them suitable partners for large-scale CS projects that do not require a high level of species knowledge. Instructors and scientific divers are well-placed to coordinate and supervise CS activities. The results confirm that divers are not all alike and specific considerations have to be taken into account to improve the contribution of each diver type to CS. The findings provide essential information for the design of different types of CS projects. By considering the relevant incentives and opportunities for diverse diver groups, marine CS projects will make efficient gains in volunteer recruitment, retention, and collaborative generation of knowledge about the marine environment.

Small-scale fisheries, which are often associated with low levels of income and poor infrastructure, receive substantial funding from governmental institutions worldwide. Very few empirical studies have explored the outcomes of these investments for people and ecosystems. This paper presents the findings of a study aimed at assessing the social and ecological outcomes of government subsidies for small-scale fisheries through an analysis of 32 fishing villages, referred to as caletas, in Chile over a 12-year period. Findings suggest that the funding appears to be higher for those caletas with the highest value landings and is unrelated to socioeconomic need or poverty; that caletas in rural areas receive less investment than their urban counterparts; that funding did not lead to a positive improvement in either the landings or income for fishers; and, finally, that funding appears to be a consequence of, rather than a reason for, the ecological and productive history of fisheries. These findings challenge two assumptions informing the debate about subsidization in small-scale fisheries: first, that subsidization will lead to over-exploitation, and second, that subsidies are supplied to alleviate poverty.

Temperature generally drives latitudinal patterns in the strength of trophic interactions, including consumption rates. However, local community and other environmental conditions might also affect consumption, disrupting latitudinal gradients, which results in complex large‐scale patterns. This study assessed the relative effect of environmental variables and local consumer communities on predation and herbivory along more than 22 degrees of latitude (∼2500 km) of the Chilean coast. Consumption assays with animal prey (porcellanid crabs and squidpops) and the kelp Lessonia spp. were used to assess predation (after 2 h and 24 h) and herbivory (after 24 h) at 12 study sites where important environmental variables (seawater characteristics, habitat features and consumer community characteristics) were measured. For each prey type, we aimed to identify the variables that best explained variation in consumption. Predation rates were positively related to temperature, but also with dissolved oxygen and higher salinities, all variables that are thought to favour higher metabolic rates in consumers. Local habitat characteristics (i.e. higher bare rock cover) negatively affected predation rates on porcellanid crabs, likely because large predatory fish feeding on crabs (which also explain higher crab consumption) are less abundant in seaweed‐free areas (kelp or understory algae). There was a decrease in herbivory with higher understorey algae cover, possibly due to the presence of alternative, more palatable seaweeds. The fact that the offered kelp blades were not consumed at latitudes where phlorotannin contents were very high suggests a relationship between consumption and seaweed palatability. Since many of the explanatory variables did not show a strict latitudinal trend, large‐scale consumption patterns can vary with sources of local variation that affect the consumer metabolism, foraging efficiency and consumption pressure.

The porcellanid crab Allopetrolisthes spinifrons, a symbiont of the sea anemone Phymactis papillosa, shows a suspension-feeding behavior related to flow oscillations (repetitive changes of flow direction). Individual crabs oriented their filter appendages (third maxillipeds) to maintain a concave face upstream, showing a higher frequency of maxilliped movements (flexion) at the start of inverted flow. The crab is primarily a suspension feeder that can ingest host mucus and feces. Contrary to free-living porcellanids, the symbiotic life-style offers access to exposed sites in the intertidal and subtidal environments that are favorable for passive suspension-feeding activities and consequently, an alternative feeding mechanism is not necessary.

Territorial User Rights in Fisheries (TURFs) have spread in Chile, since the late 1990s, in the form of commons institutions. TURFs are presented by some scholars as a social-ecological success; by others as showing economic and compliance problems. Studies looking at the material conditions in which fishers produce and reproduce their livelihoods, and in which TURFs emerge, are scarcer. Ostrom’s theory on the commons claims that certain collective action conditions have to be met to become thriving commons institutions. Our hypothesis is that while institutions are moulded by local material conditions, such as geographical location and social embeddedness, these impose challenges and constraints upon fishers influencing TURFs’ long-term viability. How are collective action conditions influenced when the new TURFs commons do not emerge in tabula rasa contexts but in occupied spaces? Do material conditions influence TURFs’ sustainability? This paper set out to explore these conditions. Huentelauquén’s and Guayacán’s TURFs (central-northern Chile) were chosen, as they represent two extremes (rural-urban; on private property-on State/municipal property; mainly diver – mainly fisher) contexts in which TURFs have emerged. We mainly used Participatory Rural Approach (PRA) tools triangulated with other qualitative methods. This study shows that both social embeddedness (private/State lands), and geographical location (rural/urban) matter, resulting in different access to the coast for different TURFs, thus determining some important differences between our cases in at least three relevant areas: entrance, social relations between the fishers’ organization (entitled the TURFs) and the landowner (private or municipal/State) and the existence or absence of fishing and general infrastructure. Competition for space among key actors seems to affect the process of acquiring a TURF as well as the conditions conductive to collective action. TURFs’ assessments should therefore consider both, the local particularities of specific fishing communities and the larger structural context in which they emerge, that if not paid attention to, can weakens TURFs’ viability for sustainable fisheries.