Resolving future fire management conflicts using multicriteria decision making

Management strategies to reduce the risks to human life and property from wildfire commonly involve burning native vegetation. However, planned burning can conflict with other societal objectives such as human health and biodiversity conservation. These conflicts are likely to intensify as fire regimes change under future climates and as growing human populations encroach farther into fire‐prone ecosystems. Decisions about managing fire risks are therefore complex and warrant more sophisticated approaches than are typically used. We applied a multicriteria decision making approach (MCDA) with the potential to improve fire management outcomes to the case of a highly populated, biodiverse, and flammable wildland–urban interface. We considered the effects of 22 planned burning options on 8 objectives: house protection, maximizing water quality, minimizing carbon emissions and impacts on human health, and minimizing declines of 5 distinct species types. The MCDA identified a small number of management options (burning forest adjacent to houses) that performed well for most objectives, but not for one species type (arboreal mammal) or for water quality. Although MCDA made the conflict between objectives explicit, resolution of the problem depended on the weighting assigned to each objective. Additive weighting of criteria traded off the arboreal mammal and water quality objectives for other objectives. Multiplicative weighting identified scenarios that avoided poor outcomes for any objective, which is important for avoiding potentially irreversible biodiversity losses. To distinguish reliably among management options, future work should focus on reducing uncertainty in outcomes across a range of objectives. Considering management actions that have more predictable outcomes than landscape fuel management will be important. We found that, where data were adequate, an MCDA can support decision making in the complex and often conflicted area of fire management.     

Gillnet illumination as an effective measure to reduce sea turtle bycatch

The growing demand for fish around the world is an immediate threat to marine megafauna that are unintentionally captured in commercial and artisanal fishery operations. Bycatch mitigation strategies, such as turtle excluder devices, circle hooks, and net illumination, have successfully reduced this risk in some fisheries. We explored the effectiveness of gillnet illumination to reduce sea turtle captures in 2 artisanal fisheries (Mankoadze and Winneba, Ghana) under normal fishing conditions. We first quantified sea turtle bycatch in Ghana's artisanal gillnet fishery from 15 boats for 12 months. We then quantified catch of targeted species and sea turtle bycatch from 20 boats for 15 months (7427 net sets). For 10 of these boats, we placed a Centro Economy green light (1 LED) at each 10-m interval on the net. We also quantified target catch and sea turtle bycatch from 30 boats for 8 months (2250 net sets). In 15 of these boats, a Centro Deluxe green light (3 LEDs) was installed at 15-m intervals. Boats with economy lights and those with deluxe lights both exhibited an 81% decrease in sea turtle captures (W = 1, p < 0.001, n = 20; W = 215, p < 0.001, n = 30, respectively) compared with control boats without lights. Illuminated nets resulted in fewer turtle catches for leatherback (Dermochelys coriacea), olive ridley (Lepidochelys olivacea), and green sea turtles (Chelonia mydas) (p < 0.05 for all species). Target catch (mass) (W = 53, p = 0.853 n = 20; W = 76, p = 0.449, n = 23) and value (W = 50, p = 1, n = 20; W = 69, p = 0.728, = 23) were not different across treatments. Our study affirms net illumination can reduce capture rates of 3 species of sea turtles, including the imperiled leatherback. Gear modification methods can successfully reduce bycatch if they are affordable and have broad applications for multiple species in different fisheries.     

Transmitter attachment and release methods for short-term shark and stingray tracking on coral reefs

This study details a simple and cost-effective means of attaching acoustic transmitters to coral reef sharks and stingrays, which potentially allows for retrieval and reuse on completion of tracks. Between 2008 and 2011, galvanised timed releases were trialled in both static field tests and on blacktip reef sharks Carcharhinus melanopterus, cowtail Pastinachus atrus, and porcupine Urogymnus asperrimus rays in Coral Bay (?23°08′41″, 113°45′53″), Western Australia. The timed releases remained attached to animals for the duration required for tracking and in four out of five deployments transmitters were recovered after release from the animals. The use of modified Rototags for sharks and stainless steel darts for stingrays allowed rapid and effective attachment to animals, with limited impact on their welfare in the short term. External attachment for short-term tracking of coral reef-associated elasmobranchs should be considered as a complementary option to internal placement of transmitters in animals either by surgery or by ingestion.     

Small-scale spatial and temporal genetic structure of the Atlantic sea scallop (Placopecten magellanicus) in the inshore Gulf of Maine revealed using AFLPs

Despite long planktonic durations, many species of broadcast spawning invertebrates exhibit genetic structure at small spatial and temporal scales. Amplified fragment length polymorphisms were used to assess genetic variation in the sea scallop, Placopecten magellanicus, among four inshore and one offshore location in the Gulf of Maine and temporal genetic variation among age classes of sea scallops at one site. Our results indicated that genetic structure for P. magellanicus exists on smaller spatial scales (tens to hundreds of kilometers) than expected given the 40-day planktonic larval period. In addition, genetic differences among age classes may be influenced by inter-annual differences in larval supply or reproductive success. Future genetic studies should sample multiple age classes prior to comparison among locations.     

Hematological responses of broiler chickens exposed to simulated crude petroleum emissions

Hematological responses of broiler chicken exposed to simulated crude petroleum emissions at varying distances over a period of 16 h daily were evaluated for 56 days in a poultry house. The burning of crude petroleum was simulated with a specially designed burner. The measured distances were 4, 8, or 12 m from the flame point. Control birds were located in a separate poultry building without the flame treatment. Gaseous emissions from the burning crude oil were monitored. Proprietory broiler starter and finisher diets were fed ad libitum. Blood samples were taken at the fourth and eighth weeks for hematological assay from each treatment. The hematological parameters assayed were hemoglobin (Hb), packed cell volume (PCV), white blood cells (WBC), neutrophils, and lymphocytes. Results indicated that the treatment did not significantly affect the Hb, PCV, and WBC constituents. Neutrophils significantly decreased while lymphocytes increased. The age of birds significantly increased Hb, PCV, and WBC levels in the blood.     

Hormonal responses of broiler chickens to simulated crude petroleum flame and fumes

Hormonal responses of broiler chickens exposed to crude petroleum flame and fumes at varying distances over a period of 16 h daily were evaluated for 56 days in a poultry house. The burning of crude petroleum was simulated in a designed burner. The measured distances were 4, 8, or 12 m from the flame point. The experimental design was a two-factor factorial in a completely randomized design (CRD) with factor A as distance from the crude petroleum flame and factor B was the age of birds in weeks. One hundred and eighty Anak day-old broiler chickens were divided into four groups of 45 birds each, replicated thrice at 15 birds per replicate. Control birds were located in a separate poultry building without the flame treatment. Gaseous emissions from the burning crude oil were monitored. Proprietary broiler starter and finisher diets were fed ad libitum. Blood samples were taken at the fourth and eighth week for hormone radioimmunoassay from each treatment. The hormones assayed were growth hormone (GH), thyroxine (T₄,), and adrenaline. Results indicated that treatments did not significantly alter hormonal levels. The age of birds significantly affected the levels of all three hormones measured.     

Mind the gap: a comparative study of migratory behavior in social amoebae

Social amoebae aggregate to form a multicellular slug that migrates some distance. Most species produce a stalk during migration, but some do not. We show that Dictyostelium giganteum, a species that produces stalk during migration, is able to traverse small gaps and utilize bacterial resources following gap traversal by shedding live cells. In contrast, we found that Dictyostelium discoideum, a species that does not produce stalk during migration, can traverse gaps only when in the presence of other species’ stalks or other thin filaments. These findings suggest that production of stalk during migration allows traversal of gaps that commonly occurs in soil and leaf litter. Considering the functional consequences of a stalked migration may be important for explaining the evolutionary maintenance or loss of a stalked migration.     

Flexible foraging strategies in a diving seabird with high flight cost

How central-place foragers change search strategy in response to environmental conditions is poorly known. Foragers may vary the total distance travelled and how far they range from the central place in response to variation in the distribution of their prey. One potential reason as to why they would extend the length of their foraging trip and its distance from the colony would be to increase prey quality or quantity, despite incurring higher transit costs. To test this trade-off hypothesis in a species with high flight costs, we recorded the foraging behaviour of razorbills (Alca torca) using state-of-the-art techniques that log both individual horizontal (flight activity) and vertical (dive activity) movements. We show that the distance that razorbills travelled to foraging locations increased with sea-surface temperature, which may relate to higher prey quality or quantity. This relation is supported by an indirect index of patch quality, based on dive profiles, which also increased with travel distance from the colony. Furthermore, we show that this index was highest during the daily peak in diving activity, around midday. Taken together, these results suggest that razorbills are capable of adjusting their search strategies sensitively in response to proximate environmental cues.     

Consumption-based accounting of CO2 emissions in the sustainable development Goals Agenda

In 2017 the paper ‘The Sustainable Development Oxymoron: Quantifying and Modelling the Incompatibility of Sustainable Development Goals’ was published, showing that there is a conflict between socio-economic development goals and ecological sustainability goals using cross-country time-series data. The authors looked at production-based CO2 emissions to measure and model the 13^th SDG goal addressing climate change. Their models showed that production-based CO2 emissions were stalling or even decreasing in rich countries, which suggests that other countries are also likely to see stalling and decrease in their CO2 emissions once they become rich. However, this conclusion can be challenged when accounting for consumption-based CO2 emissions rather than production-based CO2 emissions. In this follow-up paper, we re-run some of the analyses performed in the original paper making use of consumption-based CO2 emissions. The analysis confirms the inherent SDG conflict between socio-economic and ecological SDGs. But, this new analysis demonstrates that from a consumption perspective the trend of stalling or decreasing CO2 emissions is reversed, with natural depletion costs being exported to poorer countries. Despite this new perspective on CO2 emissions, the conflict between SDG goals can still be avoided by making investments in public health, education and renewable energy, as suggested in the original paper.