Seafloor Imaging and Toxicity: Assessment of Risk caused by buried waste SITAR

1
Seafloor Imaging and Toxicity Assessment of Risk
caused by buried waste SITAR
Results (1) To meet the project objectives, SITAR
is investigating scientific and technological
tools for the needs of dump-sites survey and
investigation these include the stages of
localization, inspection, bioassessment, data
integration and evaluation. Localization SITAR
is developing a bottom penetrating parametric
side-scan sonar (SSS) instrument, that
acoustically image the sub-bottom by using both
high and low frequency signals. The instrument is
complemented with innovative 3-D synthetic
aperture sonar processing (SAS), to enhance data
quality and facilitate image interpretation. A
prototype has been tested in the field on
Sep-Oct 2003, over an existing dump site in the
Baltic Sea. SAS processing is currently
on-going. Inspection Once localized, a
potential waste container has to be inspected to
assess its true nature and hazard. Video
inspection is ineffective on buried containers.
SITAR is developing an acoustical imaging
technique based on Multiple Aspect Scattering
measurements (MAS) from the buried container.
Scaled tank experiments to test the technique in
controlled conditions have been completed, and
field data have been collected in the Sep-Oct
2003 cruise.
Partners ISME, Interuniversity Ctr. Integrated
Sys. Marine Env., Italy ECAT, Environmental Ctr.
Administration and Tech., Lithuania UBAH.PHY,
Dept. Physics, Univ. of Bath, United
Kingdom ARMINES/ECOLE NAVALE, Naval Acad. res.
ctr. , France FOI, Swedish Defense Research
Agency, Sweden KTH, Royal Institute of
Technology, Sweden KDA, Kongsberg Defense and
Aerospace, Norway NTNU, University of Trondheim,
Norway SU, Stockholm University, Sweden SEPA,
Swedish Environmental Protection Agency,
Sweden website http//www.isme.unige.it/sitar
 

• Objectives
• SITAR main objective is the development of
  enabling technologies for risk assessment of
  shallow water dump sites
• Specific objectives are
• development of acoustic methods and
  instrumentation for imaging of waste containers
  of small dimension buried in unconsolidated sea
  sediments
• development of biological testing methods for
  determination of in-situ bioaccumulated toxicity
• integration of acoustical imaging data and
  biotoxicological information for end-users
  (decision makers).

Parametric SSS data. Left high frequency image
(110 kHz) Right low frequency (18-20 kHz) image
of the same bottom area. The bright spot
corresponds to a buried anomaly
EUROCEAN 2004, GALWAY IRELAND, SLIDE 1
2
Seafloor Imaging and Toxicity Assessment of Risk
caused by buried waste SITAR
Relevance for society Toxic dumping at shallow
water sites and in close seas has been forbidden
since the London convention (1975), although it
is known that covert practice has taken place, in
Europe and elsewhere. Pre-London dumpings have by
now undergone partial or complete burial in the
seabed sediment. Even for known sites there is
lack of information on amount of containers,
state of preservation, environmental exposure to
toxic agents. A significative (and not unique)
case is the chemical munition dumping in the
Baltic Sea, in the post WW-II years, where the
dumping is estimated to amount to 65,000 tons of
toxic warfare agents. Video inspection shows the
preservation state of containers varying from
totally corroded to perfectly preserved. Amount
and location of buried containers is unknown.
Existing technology and analysis methods are
poorly efficient, if not totally uncapable, of
localizing and inspect buried containers, and to
measure in a realistic way the bioaccumulated
toxicity in the environment due to prolonged
exposure to slowly released contaminants.
SITAR is providing and testing the
technological and scientific tools able to cope
with the present lack of means for a correct
assessment of risk of buried dumpings in the
seafloor. The availability of new-generation
methodologies will make it feasible in a
cost-effective way the systematic surveys of
known and suspected dumpings. Integrated
presentations will make the new data accessible
in a user-friendly way to decision-makers,
favouring a rational management of seabed dumping
sites.
Results (2) Bioassessment SITAR efforts are
focused on bioaccumulated toxicity evaluation, in
contrast with traditional acute toxicity
analysis. The project is developing and testing
the technique of nanoinjection into fertilized
fish eggs of extracts from bottom samples. The
observed percentage of growth disorders, when
compared with the percent disorders resulting
from extracts of a known reference site, gives a
relative measure of accumulated toxicity. The
technique mimics maternal exposure and food
uptake. It is species and pollutant independent.
Analysis of samples from the study site is
on-going Data integration and evaluation A
GIS-based data presentation system is being
developed, on specification from final end-users.
The GIS system includes a Decision Support System
(DSS) for buried containers image analysis and
inspection. The DSS works on 3-D images from the
MAS data, with tools as 3-D acoustic image
segmentation, feature extraction, rendering and
virtual navigation. The overall GIS system
includes at the moment the historical data at the
survey site, plus the first processed data made
available from the Sep-Oct 2003 experiment.
 
Left nanoinjected egg and fish larvae with
different growth disorders Right SSS,
bathymetry and containers density at the study
site on interactive GIS map

EUROCEAN 2004, GALWAY IRELAND, SLIDE 2