Slaven Reljić

New directions in management strategy evaluation through cross-fertilization between fisheries science and terrestrial conservation

On 1 and 2 June 2010, an international meeting was held at the University of Paris Sud XI, France, organized within the framework of the EU FP7 consortium project HUNT, to bring together fisheries and conservation scientists to discuss a unified framework for the future of management strategies for harvested species.

On the multifunctionality of hunting – an institutional analysis of eight cases from Europe and Africa

In many contemporary societies, multiple functions are connected to hunting. Here, we use the concept of multifunctionality to investigate the role of hunting beyond its traditional function of supplying meat. Hunting may contribute, for example, to biodiversity conservation, recreation and the preservation of economies and cultures in rural areas. Our comparative analysis of hunting in eight study sites in Europe and Africa examines the tensions and trade-offs between these ecological, economic and social functions of hunting, and investigates the interplay between the institutions regulating these functions to better understand conflicts over hunting. Based on this analysis, we present institutional arrangements that have developed to address these challenges of multifunctionality, and explore the institutional change brought about by such arrangements. Finally, we discuss the implications of this study for policy and institutional design.

Border Security Fencing and Wildlife: The End of the Transboundary Paradigm in Eurasia?

The ongoing refugee crisis in Europe has seen many countries rush to construct border security fencing to divert or control the flow of people. This follows a trend of border fence construction across Eurasia during the post-9/11 era. This development has gone largely unnoticed by conservation biologists during an era in which, ironically, transboundary cooperation has emerged as a conservation paradigm. These fences represent a major threat to wildlife because they can cause mortality, obstruct access to seasonally important resources, and reduce effective population size. We summarise the extent of the issue and propose concrete mitigation measures.

Cadmium, Lead, and Mercury Exposure Assessment Among Croatian Consumers of Free-Living Game

Abstract Free-living game can be an important source of dietary cadmium and lead; the question is whether exposure to these two elements is such that it might cause adverse health effects in the consumers. The aim of this study was to estimate dietary exposure to cadmium, lead, and mercury from free-living big game (fallow deer, roe deer, red deer, wild boar, and brown bear), and to mercury from small game (pheasant and hare), hunted in Croatia from 1990 to 2012. The exposure assessment was based on available literature data and our own measurements of metal levels in the tissues of the game, by taking into account different consumption frequencies (four times a year, once a month and once a week). Exposure was expressed as percentage of (provisional) tolerable weekly intake [(P)TWI] values set by the European Food Safety Authority (EFSA). Consumption of game meat (0.002-0.5 % PTWI) and liver (0.005-6 % PTWI) assumed for the general population (four times a year) does not pose a health risk to consumers from the general population, nor does monthly (0.02-6 % PTWI) and weekly (0.1-24 % PTWI) consumption of game meat. However, because of the high percentage of free-living game liver and kidney samples exceeding the legislative limits for cadmium (2-99 %) and lead (1-82 %), people should keep the consumption of certain game species’ offal as low as possible. Children and pregnant and lactating women should avoid eating game offal altogether. Free-living game liver could be an important source of cadmium if consumed on a monthly basis (3-74 % TWI), and if consumed weekly (11-297 % TWI), it could even give rise to toxicological concern.

Organochlorine pesticides and polychlorinated biphenyl congeners in wild terrestrial mammals from Croatia: Interspecies comparison of residue levels and compositions

In this pilot study, we investigated levels of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in the adipose tissues of two free-ranging terrestrial carnivores from Croatia sampled in 2010 and 2011: the brown bear (Ursus arctos; N=32) and the grey wolf (Canis lupus; N=29). Concentrations of ∑OCPs and ΣPCBs ranged from 0.45 to 4.09 ng g(-1) lipid mass (lm) and from 0.93 to 8.52 ng g(-1) lm in brown bear, and from 1.18 to 5.67 ng g(-1) lm and 2.68 to 48.9 ng g(-1) lm in grey wolf adipose tissues, respectively. PCBs were dominant accounting for over 72% of total analyzed persistent organic pollutants (POPs). The sum of six indicator non-dioxin-like PCBs (Σ6IndNDL PCBs) made up 60-93% and 58-85% of the total congener concentrations in brown bears and wolves, respectively. Although the levels of the measured parameters were significantly higher in grey wolves than in bears, the contaminant profiles of the two species were similar, with γ-HCH, HCB, β-HCH and DDE as major OCP contaminants, and PCB-153>PCB-180≈PCB-170>PCB-138 as the dominant congeners. The sum of hexachlorocyclohexanes (ΣHCHs) and 8 toxicologically relevant dioxin-like PCBs (Σ8ToxDL PCBs) was higher in the males than in the females of the brown bear. Concentrations of ΣDDTs, HCB, ΣOCP, ΣPCBs, Σ6IndNDL PCBs, and toxicologically relevant non-dioxin-like PCBs (ΣToxNDL PCBs) were significantly positively correlated with lipid content in the grey wolf. Concentrations of OCPs and PCBs in brown bears and wolves from Croatia were low and normal for large terrestrial mammals.

Selenium in brown bears (Ursus arctos) from Croatia: Relation to cadmium and mercury

Muscle (n = 111), liver (n = 111), and kidney cortex (n = 101) samples from brown bears (Ursus arctos) were collected in the 2009 and 2010 hunting seasons in Croatia and analysed for selenium (Se), cadmium (Cd), and total mercury (Hg). The aim was to assess the levels of these elements according to age, sex, and season of collection, and to investigate possible Se/Cd and Se/Hg interactions. Median Se concentrations were 0.139 μg/g in muscle, 0.409 μg/g in liver and 1.75 μg/g wet mass in kidney cortex. Median Cd and Hg were 0.0078 and 0.0018 μg/g in muscle, 1.09 and 0.031 μg/g in liver, and 16.5 and 0.206 μg/g wet mass in the renal cortex, respectively. Se/Cd molar ratios were less than 1 in the kidney cortex, and close to or above 1 in liver and muscle, respectively. Toxic Cd and Hg correlated with Se in all of the studied tissues. Sex differences were found for all three elements (except Se in liver), with females having higher tissue concentration than males. Only Cd showed age-dependence. Bear samples collected in fall had higher Se in muscles, and Hg in muscles and liver compared to samples collected in spring. Element concentrations in brown bear tissues were within the range of previously reported studies. Bear meat is considered a rich source of Se, safe for consumption with regard to its Cd and Hg content. According to the molar ratio and correlation results, we assume that Se binding is not the primary detoxification pathway for Cd and Hg in brown bears.

Cadmium and lead in grey wolf liver samples: optimisation of a microwave-assisted digestion method.

Abstract A microwave-assisted digestion method for the determination of cadmium (Cd) and lead (Pb) by inductively coupled plasma mass spectrometry (ICP-MS) was optimised on certified reference material (CRM) (bovine liver, BCR-185R) and wolf liver samples. Different factors influencing digestion efficiency (temperature, time, composition of the digestion mixture, sample mass) were tested. Validation included linearity (up to 200 μg L-1 for Cd and Pb), detection (0.003 μg L-1 for Cd and 0.035 μg L-1 for Pb), and quantification (0.008 μg L-1 for Cd and 0.081 μg L-1 for Pb) limits. Good agreement between measured and certified values was achieved in all conditions, with recoveries ranging from 94 % to 111 % for Cd and from 95 % to 105 % for Pb. The precision of the method, expressed as relative standard deviation, was up to 3 % for Cd and 8 % for Pb. The best digestion parameters (260 °C, 30 min, 1 mL HNO3+4 mL H2O, 0.1 g of CRM) based on accuracy and precision were applied on two wolf liver samples to evaluate the need for the predigestion step (freeze-drying) and appropriate mass of the sample. Freeze-drying improved precision and minimising the tissue mass to 0.1 g reduced the matrix effect. Using these optimised digestion conditions, we determined Cd and Pb in 40 wolf livers collected in Croatia, and their medians (0.055 μg g-1 and 0.107 μg g-1, respectively) were in the range of previously reported data for the grey wolf. Sažetak KADMIJ I OLOVO U UZORCIMA VUČJE JETRE: OPTIMIZACIJA METODE RAZGRADNJE UZORAKA UZ POMOĆ MIKROVALOVA Certificirani referenti materijal (CRM) govedskih jetara (BCR-185R) i uzorci vučjih jetara koristili su se za optimizaciju metode razgradnje uzoraka prije mjerenja kadmija (Cd) i olova (Pb) masenom spektrometrijom induktivno spregnute plazme (ICP-MS). Ispitivani su različiti uvjeti koji utječu na učinkovitost razgradnje (temperatura, vrijeme, sastav otopine za razgradnju, masa uzorka). Validacijom je obuhvaćeno ispitivanje linearnosti (do 200 μg L-1 Cd/Pb), granice detekcije (0,003 μg L-1 za Cd, 0.035 μg L-1 za Pb) i kvantifikacije (0,008 μg L-1 za Cd, 0,081 μg L-1 za Pb). Postignuto je dobro slaganje izmjerenih i certificiranih vrijednosti u svim ispitivanim uvjetima uz izračunati raspon iskorištenja 94 % do 111 % za Cd i 95 % do 105 % za Pb. Najveća relativna standardna devijacija, kao mjera preciznosti, iznosila je 3 % za Cd i 8 % za Pb. Najbolji uvjeti za razgradnju (260 °C, 30 min, 1 mL HNO3+4 mL H2O, 0,2 g CRM), izabrani prema točnosti i preciznosti, primijenjeni su na uzorke vučjih jetara pri procjeni odgovarajuće mase uzorka i potrebe za uvođenjem dodatnog koraka prije razgradnje (liofilizacije). Liofilizacija poboljšava preciznost pa je preporučujemo pri pripremi uzoraka tkiva. Također, najmanja masa uzorka izabrana je ne samo zbog bolje preciznosti nego i zbog najmanjeg utjecaja matrice te potrebne količine tkiva. Medijani Cd (0,055 μg g-1) i Pb (0,107 μg g-1 mokre mase) dobiveni analizom 40 uzoraka vučjih jetara skupljenih u Hrvatskoj bili su u rasponu vrijednosti objavljenih u literaturi za sivog vuka.

Apex predatory mammals as bioindicator species in environmental monitoring of elements in Dinaric Alps (Croatia)

Tissue element investigations of apex terrestrial mammals are very scarce in Europe. We quantified 16 essential and nonessential elements in the kidney cortex, liver, and muscle tissue of 467 brown bears (Ursus arctos), 125 gray wolves (Canis lupus), one Eurasian lynx (Lynx lynx), and three golden jackals (Canis aureus) from Croatia by inductively coupled plasma mass spectrometry (ICP-MS). Renal cadmium (0.6% of animals) and lead (1%) and hepatic lead (5%) were found in toxicologically relevant levels for mammals only in bears, while the other elements were within normal range. The association of age, sex, season, and region with measured tissue elements in bear and wolf was estimated by multiple regression analyses. Age-related accumulation of cadmium was observed in bears and wolves. Lead tissue content increased with the age of bears but declined in wolves. Female bears and wolves had higher arsenic, iron, and thallium than males in some tissues. Also, cadmium, mercury, copper, zinc, selenium, molybdenum, and uranium were more abundant only in female bears. Male bears had higher potassium, zinc, and magnesium, while male wolves had higher calcium in some tissues compared to female wolves. Seasonal differences were mainly observed for bears’ tissues and region-specific differences only in wolves. The bear kidneys had the highest levels of cobalt, copper, molybdenum, cadmium, and lead among the four studied species. The element levels reported for bears and wolves represent baseline values for the Dinaric population.

A case of a brown bear poisoning with carbofuran in Croatia

Abstract We provide the first known documentation of a fatal brown bear (Ursus arctos) poisoning with carbofuran (an acetylcholinesterase inhibitor) in Croatia. Diagnosis using liquid chromatography–mass spectrometry confirmed the presence of high concentrations of carbofuran in liver and kidney tissue (12.650 and 2.695 ppm, respectively). These measurements, combined with the very small distance between poisonous baits and the brown bear carcass, provided the basis on which we concluded that the animal consumed a lethal dose of carbofuran and succumbed to acute poisoning soon thereafter. We believe this mortality was caused by the illegal placement of this poison probably to eliminate perceived pests, such as jackals (Canis aureus) or foxes (Vulpes vulpes). Our documentation may help identify similar cases and raise awareness of the risks posed by illegal poisons for non-target species, particularly scavengers such as bears.

Fellatio in captive brown bears: evidence of long-term effects of suckling deprivation?

Sexually stimulating behaviors that are not linked to reproduction are rare among non-human (especially non-primate) mammals. Such behaviors may have a function in the hierarchy of social species. In solitary species, such behaviors are more enigmatic, and possibly indicative of something abnormal. Here, we report on a case of two male brown bears, raised in captivity since being orphaned as cubs, which engaged in recurrent fellatio multiple times per day until at least 10 years old. The roles of provider and receiver in the act remained unchanged, and the behavior itself became highly ritualized. The provider always initiated the contact involving vigorous penile sucking that appeared to result in ejaculation. We suggest that the behavior began as a result of early deprivation of maternal suckling, and persisted through life, possibly because it remained satisfying for both individuals. This constitutes the first descriptive report of fellatio in bears, and suggests that some bears may suffer lifelong behavioral consequences from being orphaned at an early age.