Danielle VernaAlaska Pacific University

Pacific Ballast Water Group - April 16, 2014

Influences of policy and vessel behavior

on the risk of ballast-borne marine species invasions in

coastal Alaska

Vector-based Invasion Risk

Ruiz & Carlton 2003

Dose-Response Relationship

Wonham et al. 2013

The expected number of species that will establish is the sum of the probability of each species

establishing

Species Assemblages

Holzer 2013

Application for Alaska

Ruiz et al. 2011

Last analysis of vessel arrival & ballast discharge data in AK was for 2003 – 2004 (McGee et al. 2006)

Hotspots of invasive species along the US west coast

High potential for coastwise transfer of species (secondary spread)

US BWM Policy

2004: USCG Mandatory BWM reporting Mandatory BWM

Exemptions: Crude oil tankers involved in

coastwise tradeTraveling within one Captain of the

Port ZoneDOD & USCG vessels

2008: EPA - Vessel General Permit Regulated Pacific nearshore voyages Mandatory management & record keeping for crude oil tankers involved in coastwise trade

Ballast in AK, 2005 - 2012

~72% of ballast discharge was sourced on the US west coast or

British Columbia

Tankers discharged ~88% of all ballast

Only 33% of reported ballast was managed

(BWE)

• 3,773 discharging arrivals

• 28,213 ballast tanks • 7.5 x107 MT of ballast• 67 ports/bays• 910 offshore lat/long

Ecoregions of Alaska

Spalding et al. 2007

92%

4%

2%

Ballast in AK, 2005 - 2012

Ballast Discharge Hotspots

Valdez

Red Dog

Southeast

Dutch Harbor

Afognak

Seward

Nikiski

Ballast Discharge Volume (MT)

Reported ballast discharge in AK, 2005 - 2012

2005 2006 2007 2008 2009 2010 2011 20120.0E+00

2.0E+06

4.0E+06

6.0E+06

8.0E+06

1.0E+07

1.2E+07

1.4E+07Overseas

Year

Ball

ast

Wate

r V

olu

me

(MT

)

2005 2006 2007 2008 2009 2010 2011 20120.0E+00

2.0E+06

4.0E+06

6.0E+06

8.0E+06

1.0E+07

1.2E+07

1.4E+07Overseas

Year

Ball

ast

Wate

r V

olu

me

(MT

)

Supply & Demand?

EPA VGP

Reported ballast discharge in AK, 2005 - 2012

Risk Assessment

Reporting increase, 2008 - 2009

Anchorage

Kodiak

Valdez

99% of the increase was to the Gulf of Alaska region

Coastwise ballast: 1095% increase

Overseas ballast: 17% increase

Valdez: 1170% increase in reported ballast discharge volume

47 to 258 reporting tankers

Valdez

Seward

Nikiski

Afognak

Dutch Harbor

Red Dog

Vessel Type & Exports

Red Dog Sources

18%

82%

Managed

Unmanaged

Dutch Harbor Sources

31%

69%

Managed

Unmanaged

Valdez Sources

67%

33% Managed

Unmanaged

Model risk as a function of environmental similarity, ballast water age, ballast water volume & species richness

Between source region and top 15 ports by volume

Risk Assessment 2009 - 2012

High-latitude risk assessments:

• Baltic Sea (Leppäkoski & Gollasch 2006)

• Canada (Chan et al. 2013)

• Norway (Ware et al. 2013)

Environmental Similarity‣ (positively correlated with risk)

1) Low non-adjacent ecoregion2) Medium adjacent ecoregion3) High same ecoregion

• A weighted average was applied to the proximity ranking based on the volume of ballast per source ecoregion

Risk Framework

Spalding et al. 2007

Ballast water age (negatively correlated with

risk)

Risk Framework

• Number of days between source and discharge date

Ballast water volume (positively correlated with

risk)

• Serves as a proxy for propagule pressure

• 0.1 correction factor applied to managed ballast to represent 90% efficacy rate of BWE (Ruiz & Reid 2007)

Risk Framework

Species Richness (positively correlated with risk)

• Number of ballast-borne marine invasive species per source ecoregion (Molnar et al. 2008)

Risk Framework

 Environmen

tal Similarity

Age (days)

Corrected mean volume of ballast water

discharge: ecoregions & ports (log10MT)

Species Abundance

(1) Low < 1 > 10 < 2.6 < 110

(2) Medium 1 – 2 6 – 10 2.6 – 5.1 110 – 219

(3) High > 2 < 6 > 5.1 > 219

Risk Scale

Valdez, Nikiski, Drift River Terminal & Dutch Harbor may be hotspots for invasion

Risk to all ports was greatest from environmental similarity and ballast water volume

Past policy exemptions hindered monitoring and elevated risk

Results & Implications

Analysis of impacts from other management exemptions

(i.e. Captain of the Port Zones)

Finer-scale risk analysis

Focused management and survey efforts at source and discharge ports based on relative risk

Ballast water treatment systems

AK regulations?

Further Study

Increased Arctic vessel trafficNorthwest Passage & Northern

Sea RouteBering Strait bottleneck

Looking Ahead…

Port developmentOffshore oil & gas growth

Acknowledgements