Seismics in the environmental spotlight: counting the cost

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Seismics in the environmental spotlight counting
the cost

• Penny Barton
• University of Cambridge, England
• Tim Owen (Carrack Measurement Technology), Sean
  Gulick (University of Texas at Austin), Jaime
  Urrutia (Universidad Nacional Autonoma de
  Mexico), Joanna Morgan, Michael Warner (Imperial
  College, London), Gail Christeson (University of
  Texas at Austin), Mario Rebolledo (Centro de
  Investigacion Cientifica de Yucatan)

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Outline

• Survey target background
• Constraints prior to mobilisation
• Mitigation procedures during survey
• How the time disappeared
• What damage did we do?
• Lessons learned and conclusions

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Scientific target

• Meteorite impact crater on coast of Yucatan,
  Mexico
• Best preserved of three largest craters known on
  Earth, sealed under 1km Tertiary limestone
• Impact at 65 My, coincides with extinction of 70
  of worlds species, including dinosaurs
• One of the greatest environmental disasters in
  the history of the Earth

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Survey plan
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Environment north Yucatan coastshallow water,
flat land
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Survey parameters

• R/V MAURICE EWING
• 20 gun array totalling 6970 cu ins
• 6 km streamer
• 28 ocean bottom seismometers

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Predicted noise levels around gun array

• Measurements of same array in shallow water
  in the Gulf of Mexico gave the 180 dB safe
  radius for disturbance (but not injury or death)
  of marine mammals, at 3.5 km

• (Tolstoy et al., 2004. GRL, 31, L14310)

Tolstoy et al., 2004. GRL, 31, L14310
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CONSTRAINTS PRIOR TO MOBILISATION
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Timing of survey

• Constrained to avoid tourist season (July-Aug),
  hurricanes (Sept-Dec), peak fishing, turtle
  breeding (April-May)
• This leaves Jan-March, and June
• Academic research vessel
• scheduled far ahead
• fixed allocated time period
• operations controlled by NSF and ship operators,
  not the project leaders

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US documentation Incidental Harrassment
Authorisation (IHA)

• Compulsory for US flagged ship
• US Marine Mammal Protection Act 1972, IHA to be
  obtained from US National Marine Fisheries
  Service (NMFS)
• Authorisation to harrass (disturb) but not to
  injure or kill
• Potential harrassment incidents described as
  take
• Details of IHAs granted appear on the web

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Take estimates for this project

• Based on recorded numbers of individuals of
  different species in the Gulf of Mexico
• Best estimate was that up to 11,440 dolphins
  might be disturbed by noise of 160 dB (
  take)
• No sperm whales, beaked whales, mysticetes, seals
  expected in the area

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Take estimates for this project

• NMFS concludes
• no more than negligible impact on the affected
  species or stock

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Take estimates for this project

• NMFS concludes
• no more than negligible impact on the affected
  species or stock
• Environmentalists conclude
• Scientists are being allowed to take 11,500
  dolphins in the name of scientific progress!

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Campaign by environmentalists

• Led by Ben White of Animal Welfare Institute
• Emails from all over the world to Mexican and US
  authorities, scientists, ship operators, NSF
• Threats of local demonstrations and direct action
• sadly Ben White passed
• away August 2005

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Delays

• Ship time scheduled early 2004 but postponed
  pending completion of Mexican permitting
  procedure paperwork incomplete
• Ship time scheduled for June 2004 but postponed
  pending completion of Mexican permitting
  procedure public consultation
• Work finally took place in Jan-Feb 2005

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Mexican permits and timing

• Article 13 environmental impact assessment
  required
• Handled via SEAMARNAT, environmental ministry
• Public consultation summer 2004
• Clearance issued October 2004, notified December
  2004
• New, unacceptable, operating conditions in final
  document received when already at sea in January
  2005 re-negotiation necessary

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MITIGATION PROCEDURES DURING SURVEY
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Conditions from IHA and Mexican permits

• Monitor 3.5 km safety radius (180 dB) visually
  from ship at all times during shooting and 30
  minutes before
• Ramp-up arrays from single gun over 25 minute
  period to allow mammals to depart
• Power down gun arrays if mammals observed in this
  zone, and shut down if they enter 190 dB zone
• Similar rules for turtles
• Overflights and chase boats
• No shooting close to fishing boats

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Ben Whites blog www.sanjuanislander.com 38,047
words in 23 entries
Most things would just die and sink
Trail of dead fish
foolish gringo study by the Barco Asesino
Tools of unimaginable violence
..tied to the groundand made to watch the rape
and murder of mother ocean
100 billion times more pressure than the maximum
a human can take
Dolphins and turtles dead on the tide
could trigger another horrific earthquake
arrogant scientists with the collusion of
bought-off governments
military occupation of 1600 sq. miles of ocean
Antiquated method of obtaining information
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• Constant threat that activists would jump in
  front of the ship
• Access prevented by Mexican port authorities

Tamara Golding 2005
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Time restrictions- based on monitoring of 3.5 km
safety (180 dB) radius visually from ship
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Time restrictions- based on monitoring of 3.5 km
safety (180 dB) radius visually from ship
Night

• Daylight only (0630-1800)

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Time restrictions- based on monitoring of 3.5 km
safety (180 dB) radius visually from ship
Night

• Daylight only (0630-1800)
• Sea state not exceeding
• Beaufort 4 (wind speed

Weather
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Fisheries

• Local concern about reduced catches of fish and
  octopus
• Chase boats required
• Many small boats fishing without communication or
  propulsion
• No shooting allowed within 1.5 km of vessel
  fishing

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Marine mammal turtle observers

• Three trained observers provided by operators,
  with independent leader
• Three approved Mexican observers
• Big Eye binoculars
• Passive Acoustic Monitoring
• Instant shutdown of operations

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Overflightsair and sea searches for organisms
that may be injured as a result of airgun
operations

• 19 flights, 6604 miles, 58 hours
• No turtles sighted
• Dolphins seen on 2 flights (groups of 3-5)
• No injured organisms sighted

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Inspections

• Carried out by PROFEPA inspection arm of
  SEAMARNAT
• 5-8 people in a team
• 3 whole-day visits at sea, by boat transfer
• 822 signatures on inspection documents
• Final visit included Green Party Senator

Night
Weather
Inspections waiting for clearance
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Deploying sea bed instruments, guns and streamer,
turns while profiling, ramp-ups
Turns
Ramp-up
Night
Guns streamer
Ocean bottom seismometers
Weather
Inspections waiting for clearance
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MCS profiling
MCS profiling
Turns
Ramp-up
Night
Guns streamer
Ocean bottom seismometers
Weather
Inspections waiting for clearance
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Shutdowns due to fishing boats, turtles, dolphins
Fishing boats, turtles, dolphins
MCS profiling
Turns
Ramp-up
Night
Guns streamer
Ocean bottom seismometers
Weather
Inspections waiting for clearance
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Camera on sea bed

• Film requested by local fishing community
• Water depth 20m
• Point of closest approach approx 180m
• 6970 cu ins 20 airgun array towed at 6m depth
• Static video camera placed by diver at 3.6 km
  offset, who then got out of water
• Interestingly, diver could hardly hear the guns
  at this range

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high low
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Deaf diver?
Was our diver deaf, or were the sound levels
lower than predicted?
Open circles ray-trace model Open squares
streamer data Black diamonds ocean bottom
hydrophone data
Indications are that sound level in the water was
much lower than predicted
Preliminary results from Chicxulub survey 2005,
with thanks to J. Diebold
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Evidence of damage

• 7 shutdowns for dolphins no dead or injured
  mammals seen from ship, chase boats, spotter
  plane or on beach
• 7 shutdowns for turtles several dead turtles
  wrapped in fishing line or with stab wounds
• 15 shutdowns for fishing boats
• 3 dead fish seen floating.
• 2 dead fish on beach subject of complaint
  against the R/V EWING

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• THERE WAS NO EVIDENCE OF ANY SIGNIFICANT
  ENVIRONMENTAL DAMAGE.

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.BUT SIGNIFICANT DAMAGE TO DATA COLLECTED!

• Time reduced drastically
• Expenses increased hugely
• Holes in data from shutdowns
• Lack of fold during ramp-ups

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BUT the survey was scientifically successful!
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Conclusions-I

• Mitigation measures were successful, but were
  more than could reasonably be justified
• Issues with permits
• definitions
• e.g. what defines fishing?
• what defines sea state Beaufort 4?
• conditions that could only be fulfilled by
  others, such as the provision of approved Mexican
  mammal observers
• different conditions in different versions of the
  documents

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Conclusions-II

• Considerations for the future
• consider using a non-US flagged ship!
• avoid using a ship with a history once in the
  spotlight it is difficult to get out
• Unfortunate precedents have been set for the
  future
• Collection of further simple information (such as
  the seabed film) may provide reassurance

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