Lack of Cross-Scale Linkages Reduces Robustness of Community-Based Fisheries Management

Community-based management and the establishment of marine reserves have been advocated worldwide as means to overcome overexploitation of fisheries. Yet, researchers and managers are divided regarding the effectiveness of these measures. The “tragedy of the commons” model is often accepted as a universal paradigm, which assumes that unless managed by the State or privatized, common-pool resources are inevitably overexploited due to conflicts between the self-interest of individuals and the goals of a group as a whole. Under this paradigm, the emergence and maintenance of effective community-based efforts that include cooperative risky decisions as the establishment of marine reserves could not occur. In this paper, we question these assumptions and show that outcomes of commons dilemmas can be complex and scale-dependent. We studied the evolution and effectiveness of a community-based management effort to establish, monitor, and enforce a marine reserve network in the Gulf of California, Mexico. Our findings build on social and ecological research before (1997–2001), during (2002) and after (2003–2004) the establishment of marine reserves, which included participant observation in >100 fishing trips and meetings, interviews, as well as fishery dependent and independent monitoring. We found that locally crafted and enforced harvesting rules led to a rapid increase in resource abundance. Nevertheless, news about this increase spread quickly at a regional scale, resulting in poaching from outsiders and a subsequent rapid cascading effect on fishing resources and locally-designed rule compliance. We show that cooperation for management of common-pool fisheries, in which marine reserves form a core component of the system, can emerge, evolve rapidly, and be effective at a local scale even in recently organized fisheries. Stakeholder participation in monitoring, where there is a rapid feedback of the systems response, can play a key role in reinforcing cooperation. However, without cross-scale linkages with higher levels of governance, increase of local fishery stocks may attract outsiders who, if not restricted, will overharvest and threaten local governance. Fishers and fishing communities require incentives to maintain their management efforts. Rewarding local effective management with formal cross-scale governance recognition and support can generate these incentives

How Good Science and Stories Can Go Hand-In-Hand

What do you say when you have only a minute to explain to a municipal official why keeping track of the number of bird species found in a park may help make decisions about park management? Talk of significant differences among treatments or testing theory will likely meet with glazed looks. In contrast, sharing the stories of the citizen scientists who have censused the birds year after year makes the information more personal and more salient. Stories bring conservation science to life. When one hears how Trevor Lloyd Evans, indefatigable director of bird banding at Manomet Center for Conservation Sciences, awoke before dawn every morning, rain or shine, and led his team of volunteer banders in their mist‐netting surveys, as he has done every spring and fall for more than 40 years; how spring migrants arrive earlier than they used to; and how magical the day was when volunteers mist‐netted a Golden‐winged Warbler (Vermivora chrysoptera), a species not captured in over a decade, the significance of the issues, the contributions of science, and possible solutions become much clearer (Manomet Center 2012). We can explain, through Trevor's story, how assessments of ecosystem health are informed by long‐term observations and deep knowledge of natural and human history in particular places. Here, however, we focus on the complementary roles stories can play, together with science, in advancing conservation science and practice. We assert that conservation interventions that recognize the synergies between science and storytelling may achieve more substantial biological and social outcomes than those that rely on only one or the other. In our work as conservation scientists, we have observed at least 3 types of synergy between stories and science: stories convey the significance of our science (communication), stories can serve as data (scholarship), and stories illustrate how scientific knowledge can illuminate policy choices (translation). We illustrate these synergies with a story from Cabo Pulmo, a national park in Mexico's Baja California Sur.Keywords: Gulf of California, Conservation science, Ecosystem services, Biodiversit

Rapid Effects of Marine Reserves via Larval Dispersal

Marine reserves have been advocated worldwide as conservation and fishery management tools. It is argued that they can protect ecosystems and also benefit fisheries via density-dependent spillover of adults and enhanced larval dispersal into fishing areas. However, while evidence has shown that marine reserves can meet conservation targets, their effects on fisheries are less understood. In particular, the basic question of if and over what temporal and spatial scales reserves can benefit fished populations via larval dispersal remains unanswered. We tested predictions of a larval transport model for a marine reserve network in the Gulf of California, Mexico, via field oceanography and repeated density counts of recently settled juvenile commercial mollusks before and after reserve establishment. We show that local retention of larvae within a reserve network can take place with enhanced, but spatially-explicit, recruitment to local fisheries. Enhancement occurred rapidly (2 yrs), with up to a three-fold increase in density of juveniles found in fished areas at the downstream edge of the reserve network, but other fishing areas within the network were unaffected. These findings were consistent with our model predictions. Our findings underscore the potential benefits of protecting larval sources and show that enhancement in recruitment can be manifested rapidly. However, benefits can be markedly variable within a local seascape. Hence, effects of marine reserve networks, positive or negative, may be overlooked when only focusing on overall responses and not considering finer spatially-explicit responses within a reserve network and its adjacent fishing grounds. Our results therefore call for future research on marine reserves that addresses this variability in order to help frame appropriate scenarios for the spatial management scales of interest

Management and conservation of benthic resources harvested by small-scale hookah divers in the northern Gulf of California, Mexico: The black murex snail fishery

I conducted a management assessment for the conservation of benthic resources harvested by small-scale hookah divers in the northern Gulf of California (NG), Mexico, and analyzed the reproductive ecology of the black murex snail. Open access to the fisheries, combined with national and international market pressure, fishing methods, and the timing of fishing activities have caused an evident decline in production, the use of new fishing zones, and a shift of fishing effort towards deeper areas. However, the organization of the diving sector and its initiatives to establish forms of regulation provide an opportunity to alleviate this situation. I conclude that comanagement has the potential to be an effective management system for the benthic resources of the NG, a system that could be facilitated by the sedentary and semisedentary nature of these resources. An informal type of co-management arena is already in place with the possibility of being formalized and solidified

Marine Reserves, Community-Based Management, and Small-Scale Benthic Fisheries in the Gulf of California, Mexico

I address the emergence, governance, and effects of marine reserve efforts in the Gulf of California, Mexico, emphasizing a community-based marine reserve network established by the commercial diving sector of Puerto Peñasco, Sonora. This network emerged as a means to manage benthic resources in rocky reefs, primarily rock scallop (Spondylus calcifer) and black murex snail (Hexaplex nigritus). My study also provides an analysis of growth, reproductive ecology, and management of both species.I show that local cooperation to manage fisheries commons incorporating the use of marine reserves can emerge rapidly. Furthermore, this cooperation can be sustained in a fishery spanning no more than two generations, effectively avoiding a local "tragedy of the commons". A blend of social group characteristics, fishers' ecological knowledge and participation in monitoring, and relatively rapid ecological response of the system can play key roles in reinforcing cooperation.I provide evidence of rapid effects of reserves on adjacent fisheries via larvae dispersal. Visual censuses revealed that density of young rock scallop (individuals recruited since reserve establishment) had increased by up to 40.7% within coastal reserves and by 20.6% in fished sites in only two years. Changes were also evident for black murex, with more than a three-fold increase in the density of juveniles within fished sites. These effects, however, were spatially-constricted, evident only for the northern portion of the reserve network. These empirical findings are more indicative of a reserve effect rather than other confounding factors and are consistent with field oceanography data (release of satellite-tracked drifters) and outputs from larvae dispersal models.Finally, I show that just as cooperation can emerge, it can rapidly fall with cascading effects to the system's resilience, particularly amidst threats to social capital and pressure from outside the community. I conclude that even when community-based reserves are effective within the biophysical and local social context, their long-term efficacy will rely on the system's capacity to control access and will demand the institutional capacity to do so. In Mexico this implies, at the least, the government's formal recognition of community-based initiatives and a means to give viability to these efforts

Changes in length and mass of rock scallops (<i>Spondylus calcifer</i>) and black murex snails (<i>Hexaplex nigritus</i>) before and after reserve establishment.

<p>(a) Comparison of the average adductor muscle length and mass of rock scallops from fishing areas (2002 = Spring, two months before reserve establishment). Data from reserves was not obtained as animals would have needed to be sacrificed. (b) Comparison of the average live mass of black murex snails from reserve and fishing areas.</p

Rules and levels of compliance before and after entrance of roving bandits^†.

†<p>Compliance levels based on percentage of fishers known to have broken the rule at least once: 1 = very low (<10%), 2 = low (10–40%), 3 = moderate (41–60%), 4 = high (61–90%), 5 = very high (>90%). Time A = June 2001–May 2004, Time B = first six months (June–November 2004) after entrance of roving bandits.</p

Rapid rise and fall of San Jorge Island fishery stocks from summer 2002, when the Puerto Peñasco community-based reserve network was established, to the end of summer 2004, three months after roving bandits poached on the island.

<p>The graph depicts differences in relative densities (S.E. bars included) from one monitoring season to another for the main species harvested: murex snails (<i>Hexaplex nigritus</i>) and rock scallops (<i>Spondylus calcifer</i>).</p

Community-based marine reserve network of Puerto Peñasco and sequential phases of poaching.

<p>During the first phase (green), divers from other locations, “roving bandits”, poached on the San Jorge Island reserve. This was followed by local rule breaking and some divers from Puerto Peñasco poaching on the Island (second phase, pink arrows). During the third phase (yellow), all members of the Puerto Peñasco diving cooperative broke their local rules and coastal reserves were targeted. It took less than two months for rules to be broken by all local divers after entrance of roving bandits.</p

Formal and informal sanctions by rule type devised by local fishers.

<p>Formal and informal sanctions by rule type devised by local fishers.</p