Slide 1

Mercury in biota in the Tyrrhenian Sea Pilot Study 2011MEDOCEANOR ProjectFenice workshop, March 27, 2012

Oksana Lane, David Evers Biodiversity Research Institute, Maine and Kate Buckman- Dartmouth college, New Hampshire, USA

1Study Area Tyrrhenian /Mediterranean Sea

All sites w/in Terrr. Sea2

Pelagic Food Web

+suro

3OutlineSurface water sampling/resultsZooplankton sampling/resultsMegafauna: fish and calamari sampling/resultsHuman hair on board Urania results

Taxa collectedZooplankton: copepods, euphausiids, salpsTiny fish (1-2 cm); lantern fishBenthic invertebrates: annalida, etcCephalopods: calamari and totanoPredatory fish-Suro=Mediterranean Horse MackerelFish from the stomachs of SuroHuman hair on board UraniaAlso filtered water samples were analyzed

5Collection methods for surface water

Rosetta; biology was filtered out and remaining water was analyzed for THg6Surface water resultsHg in filtered surface water was below detection limits for all sitesDissolved Cd, Pb, Sn, Zn, & Cu all below reporting limitsMeasurable dissolved As & Se, As but not Se different across sites

Preliminary analyses of particulates were near detection limits for MeHg & inorganic Hg, needs additional sample analysisSiteRos-SolLivornoPiombinoOpen Sea 2StromboliLipariMean As (ppb)3.313.032.822.022.322.07TukeysAA,BA,BCB,CC

Arsenic and selenium the only 2 above det. Limit and were slightly higher at the industr. sites7Collection methods-ZooplanktonNeuston net-1/2 x 1 x 5m; day and night time towingTwin ring net (60cm diameter); for water column sampling

We towed for 30 min at 2knots/hr. Many taxa of zooplankton undergo vertical migration and come up to the surface at night. Typically night tows were more productive8Zooplankton Euphausiid

Isopods and megalope

Photos by Kate Buckman

Neat-looking thingsSmall (1-2 cm smelt/alici?) and a myctophid (lantern fish)

Results: Hg speciation in ZooplanktonTo our knowledge, this is the first measurement of Hg & MeHg in field sampled zooplankton from the Mediterranean, as well as the first measures on euphausiids.Euphausiids eat phytoplankton and small zooplankton and likely have slightly higher trophic status than the small fish. Life span~1 month.3 composite samples per site, alpha = 0.05, Tukeys HSD used to assess pairwise differences.

11Sampling methods for megafauna

Fish line and bait on hook=primitive but works12Mediterranean horse mackerel=Suro (Trachurus mediterraneus)CarnivoreDiet: zooplankton=Crustacea: Euphausiids, Mysidacea, Decapods Teleostei (fish) and Cephalopoda (calamari) Polychaeta (annelid worms) Important commercially

Stomach contents of Suro, October 2011.

13Squid=Calamari, totanoCephalopods (phylum: molluska)PredatorImportant food source for marine mammals, fish, humansDiet: fish, crustaceans, other squids

THg concentrations (g/kg=ppb) 2011in 3 taxa from Livorno.Figure 2. Blood Hg concentrations in Alaskan shorebirds. Lines show blood mercury levels associated with 10% (0.7 g/g), 20% (1.2 g/g), 30% (1.7 g/g) reduced nesting success based on the Carolina wren model. All juveniles and adult ROSA sampled during migration; adult DUNL, REPH, and SESA sampled during breeding season at Barrow, AK. ROSA = rock sandpiper, DUNL= dunlin, REPH= red phalarope, SESA= semipalmated sandpiper.AdultJuvenileROSADUNLREPHSESAMaximumMean + Standard Deviation30% reduction20%10%Station=LivornoMuscle-HgMean St devnumberStomach fish from Suro(anchovies=alici)3314.72 Calamari6940.83 Suro=Med. Horse mackerel191948

A total of

15Mean THg in Suro muscle( wet wt. ppm) Wilcoxon nonparametric test: Piombino >Ustica, p=0.0085; Livorno >Ustica, p=0.052

Red line represents 0.3 ppm=recommended (by US EPA)upper level for human consumption of contaminated fish and wildlife. Dashed yellow line represents 0.15 ppm=threshold level for piscivorous wildlife0.15 ppm effect level for wildlife consumption (based on fish-eating birds, mammals in fresh water systems)16Suro size

Fish length in cm of Mackerel (Suro) analyzed for Hg, 2011. There is no statistical difference in fish length among sites, p>0.1

Therefore higher Hg in Piombino samples is not related to fish size and is likely due to local pollution.17Comparison of calamari/totano Hg (g/g, fw) by site, 2011

Over 90% of total Hg was MeHg in mackerel and calamari. Piombino is significantly higher than other sites, p