Toxic and essential elements in seafood from Mausund, Norway

Area of Science:

• Environmental Science
• Marine Biology
• Analytical Chemistry

Background:

• Annual surveys (2012-2015) assessed toxic and essential element concentrations in commercially important Norwegian seafood.
• The study focused on edible crab (Cancer pagurus), cod (Gadus morhua), and halibut (Hippoglossus hippoglossus) from a key fishing area in Mausund, Norway.
• The research area hosts several salmon farms, necessitating an investigation into potential impacts on local marine life.

Purpose of the Study:

• To analyze concentrations of 15 elements (B, Se, Cd, Sn, Cs, Hg, Pb, Al, Cr, Mn, Fe, Ni, Cu, Zn, As) in seafood and sediments.
• To determine if element concentrations varied significantly between different locations and over the survey years.
• To investigate potential correlations between element levels in seafood, sediments, and the proximity of salmon farms.

Main Methods:

• Seafood samples (crab, cod, halibut) were collected from five locations, including one near a salmon farm.
• Sediment samples were collected in 2015 for elemental analysis.
• Samples were prepared using nitric acid extraction and analyzed via inductively coupled plasma mass spectroscopy (ICP-MS).

Main Results:

• Edible crabs showed significantly different mean ranks for tin (Sn) between two locations.
• Crab populations exhibited significant annual variations in selenium (Se), cesium (Cs), manganese (Mn), zinc (Zn), and arsenic (As). Elevated cadmium (Cd) levels were observed annually, peaking in 2015.
• Cod displayed significant location-based differences for boron (B) and lead (Pb), and annual differences for B, Sn, Cs, mercury (Hg), chromium (Cr), and As. Elevated lead (Pb) was noted in 2013. Halibut showed no significant variations.

Conclusions:

• While some elements varied significantly in crabs and cod over time and location, halibut remained unaffected.
• Sediment analysis indicated that local geogenic sources were unlikely to be the primary cause of elevated Cd, Hg, and Pb in the studied biota.
• The study highlights the importance of continuous monitoring of elemental concentrations in commercially important seafood species within potentially impacted marine environments.