Resilient livelihoods and food security in coastal aquatic agricultural systems: Investing in transformational change

Aquatic agricultural systems (AAS) are diverse production and livelihood systems where families cultivate a range of crops, raise livestock, farm or catch fish, gather fruits and other tree crops, and harness natural resources such as timber, reeds, and wildlife. Aquatic agricultural systems occur along freshwater floodplains, coastal deltas, and inshore marine waters, and are characterized by dependence on seasonal changes in productivity, driven by seasonal variation in rainfall, river flow, and/or coastal and marine processes. Despite this natural productivity, the farming, fishing, and herding communities who live in these systems are among the poorest and most vulnerable in their countries and regions. This report provides an overview of the scale and scope of development challenges in coastal aquatic agricultural systems, their significance for poor and vulnerable communities, and the opportunities for partnership and investment that support efforts of these communities to secure resilient livelihoods in the face of multiple risks.

Building climate-resilient food systems for Pacific Islands

The countries and territories of the Pacific Islands face many challenges in building the three main pillars of food security: availability, access and appropriate use of nutritious food. These challenges arise from factors including rapid population growth and urbanization, shortages of arable land for farming and the availability of cheap, low-quality foods. As a result, many are now highly dependent on imported food, and the incidence of non-communicable diseases in the region is among the highest in the world. This report summarizes: 1) the projected effects of climate change on agriculture, fisheries and aquaculture in the Pacific region; 2) adaptations and supporting policies needed to reduce risks to food production; 3) gaps in knowledge that must be filled in order to implement the adaptations effectively; 4) recommendations to fill these knowledge gaps.

Resiliencia en crestas de arrecifes coralinos del este del golfo de Batabanó, Cuba, y factores determinantes probables

RESUMEN Se comparó el grado de resiliencia de seis crestas arrecifales del este del golfo de Batabanó, Cuba. Tres fueron del norte del golfo de Cazones (Tramo Norte) y las restantes, del oeste de Cayo Largo (Tramo Sur). Las del primer tramo fueron las de faro Cazones, Norte de la cresta de cayo Diego Pérez y de faro Diego Pérez. Las otras tres fueron las de cayo Rico, arrecifes Los Ballenatos y arrecifes Hijos de Los Ballenatos. Se emplearon los indicadores biológicos del Protocolo AGRRA. El Tramo Norte presentó las crestas más resilientes, sobre todo la de faro Cazones. Las del Tramo Sur no exhibieron resiliencia. Fueron varios e interrelacionados, los factores aparentemente más determinantes en la resiliencia. Entre estos, cuatro se consideraron como fuerzas motrices: resguardo contra el oleaje, circulación habitual giratoria ciclónica en la ensenada de Cazones, entrada de nutrientes provenientes tanto de la ciénaga de Zapata como de aguas profundas, y abundancia del erizo herbívoro Diadema antillarum. Los demás factores, desencadenados por los anteriores y también interrelacionados, fueron, al parecer la menor afectación por oleaje y sedimentos, estabilización de fragmentos vivos de coral, índices favorables de macroalgas bentónicas, cierta retención de nutrientes y plancton, más alimentación heterotrófica de los corales, mayor auto reclutamiento de corales y del erizo Diadema; mejores condiciones para el asentamiento y viabilidad de los reclutas, y para el recapamiento de corales; mayor crecimiento y recuperación de los corales y mejores condiciones térmicas contra el blanqueamiento de corales ABSTRACT The degree of resilience of six reef crest sites was compared at the east of the Gulf of Batabano, Cuba. Three of them were located north of the Gulf of Cazones (Northern Stretch), while the remaining ones were west of Cayo Largo (Southern Stretch). Those of the Northern Stretch were “Faro Cazones”, north of the crest of cayo Diego Pérez and “Faro Diego Pérez”. The remaining sites were those of the cayo Rico, Los Ballenatos reefs, and Hijos de Los Ballenatos reefs. The AGRRA biological indicators were applied. The Northern Stretch presented the most resilient crests, mainly that of “Faro Cazones”. Those of the Southern Stretch did not reveal signs of resilience. Several interrelated factors were apparently more linked to resilience. Four of them were considered as driving forces: shelter from waves, usual cyclonic revolving water circulation in the Ensenada de Cazones, nutrient input from the Zapata swamp and deep water, and the abundance of the herbivore sea urchin Diadema antillarum. Triggered by these driving forces, the remaining factors apparently were less effect of waves and sediments, stabilization of live coral fragments, favorable benthic macro-algae indices, some retention of nutrient and plankton, increased coral heterotrophic feeding; better conditions for recruit settlement and viability, and for coral re-sheeting; faster coral growth and recuperation and better thermal conditions against coral bleaching.

Fish recolonization in temperate Australian rockpools: a quantitative experimental approach

Understanding recolonization processes of intertidal fish assemblages is integral for predicting the consequences of significant natural or anthropogenic impacts on the intertidal zone. Recolonization of experimentally defaunated intertidal rockpools by fishes at Bass Point, New South Wales (NSW), Australia, was assessed quantitatively by using one long-term and two short-term studies. Rockpools of similar size and position at four sites within the intertidal zone were repeatedly defaunated of their fish fauna after one week, one month, and three months during two shortterm studies in spring and autumn (5 months each), and every six months for the long-term study (12 months). Fish assemblages were highly resilient to experimental perturbations—recolonizing to initial fish assemblage structure within 1−3 months. This recolonization was primarily due to subadults (30−40 mm TL) and adults (>40 mm TL) moving in from adjacent rockpools and presumably to abundant species competing for access to vacant habitat. The main recolonizers were those species found in highest numbers in initial samples, such as Bathygobius cocosensis, Enneapterygius rufopileus, and Girella elevata. Defaunation did not affect the size composition of fishes, except during autumn and winter when juveniles (<30 mm TL) recruited to rockpools. It appears that Bass Point rockpool fish assemblages are largely controlled by postrecruitment density-dependent mechanisms that indicate that recolonization may be driven by deterministic mechanisms.