Micro-X-ray fluorescence image analysis of otoliths to distinguish between wild-born and stocked river-spawning whitefish captured in the Baltic Sea

Strontium concentrations are low in fresh waters compared to seawaters. Therefore, wild-born river-spawning and stocked freshwater-reared whitefish Coregonus lavaretus L. display regions with low concentrations of strontium in the centre of their otoliths. Strontium in otoliths from wild-born river-spawning whitefish ascending the River Tornionjoki, river-spawning whitefish stocked as one-summer-old fingerlings caught ascending the River Kemijoki, and sea-spawning whitefish caught near the angstrom land Islands was mapped using mu-XRF. The strontium-depleted regions in the centre of the whitefish otoliths, measured using ImageJ, had mean sizes of 0.18 +/- 0.2 mm(2) (River Tornionjoki) and 2.3 +/- 0.3 mm(2) (River Kemijoki), whereas the otoliths from whitefish caught at sea lacked a strontium-depleted region altogether. Measurement of the area of the strontium-depleted region in whitefish otoliths provides a convenient method with which to differentiate between whitefish of different provenance and to determine the origins of whitefish in mixed catches

Prevalence of stocked whitefish in River Kemijoki, Finland, inferred by micro X-ray fluorescence analysis of otoliths

Micro X-ray fluorescence (mu-XRF) analysis of otoliths was evaluated as a method to estimate the proportion of stocked one-summer-old whitefish Coregonus lavaretus L. in catches of adult fish (n = 20) ascending the River Kemijoki to spawn. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analysis was applied as control. Polished otoliths were scanned with mu-XRF to obtain strontium maps that were used to infer visually the provenance of the whitefish. Thirteen of the fish showed signs of being stocked as one-summer-old fingerlings. LA-ICP-MS was applied to determine the elemental composition in a spot outside the core of the otolith. The results were largely consistent with the visual inspection of the mu-XRF mapped otoliths. In conclusion, mu-XRF mapping successfully identified whitefish stocked as one-summer-old fingerlings. The vast majority of whitefish returning to the River Kemijoki to spawn were stocked fish

The Contract as Social Artifact

This article outlines a distinctive, albeit not entirely unprecedented, research agenda for the sociolegal study of contracts. In the past, law and society scholars have tended to examine contracts either through the intellectual history of contract doctrine ‘‘on the books’’ or through the empirical study of how real-world exchange relations are governed ‘‘in action.’’ Although both of these traditions have contributed greatly to our understanding of contract law, neither has devoted much attention to the most distinctive concrete product of contractual transactionsFcontract documents themselves. Without denying the value of studying either contract doctrine or relational governance, this article argues that contract documents are independently interesting social artifacts and that they should be studied as such. As social artifacts, contracts possess both technical and symbolic properties, and the sociolegal study of contract-as-artifact can profitably apply prevailing social scientific theories of technology and symbolism to understand both: (1) the microdynamics of why and how transacting parties craft individual contract devices, and (2) the macrodynamics of why and how larger social systems generate and sustain distinctive contract regimes. Seen in this light, the microdynamics of contract implicate ‘‘technical’’ theories of transaction cost engineering and private lawmaking, and ‘‘symbolic’’ theories of ceremony and gesture. In a parallel fashion, the macrodynamics of contract implicate ‘‘technical’’ theories of innovation diffusion, path dependence, and technology cycles, and ‘‘symbolic’’ theories of ideology, legitimacy, and communication. Together, these micro and macro explorations suggest that contract artifacts may best be understood as scripts and signalsFcollections of symbols designed to field technically efficacious practical action when interpreted by culture-bearing social actors within the context of preexisting vocabularies and conventions