Extending SMA’s by 10 NM to Reduce Vessel Strikes with North Atlantic Right Whales

Abigail Szczepanek, major Natural  Resource Conservation

Hannah Davin, major Environmental Science

Beau Salamon-Davis, major BCT

Most animals names are derived from greek or latin terms, describing their looks or features. The North Atlantic right whale (NARW) is a special case. The right whale coined its name some time in the 17th or 18th century when whaling was becoming popular. Crane (2002) and National Geographic (2018) say they were considered the “right” whale to hunt because they are surface feeders, slow swimmers, yield high amounts of oil, meat and bone, and they float when they are dead. This made them easy targets and were hunted for nearly three centuries. Whalers would either shoot or throw a whale iron, otherwise known as a harpoon, into a whales blubber to create a connection between their boat and the whale. They would pull themselves in closer to the whale and plunge a barbed weapon into the whales lung or heart, ultimately killing it (New Bedford Whaling Museum, 2018). By 1937 there were less than 100 NARW left and commercial whaling was banned internationally (Marine Mammal Science, 2018). The whale was placed under the Endangered Species Act in 1970 (NOAA, 2018). Currently there are only 450 NARW’s left in the Atlantic Ocean and complete extinction is nearing within the next century (Gibbins, 2018).

The NARW population was believed to be a few hundred in 1970, showing a small but steady population growth since 1937 (Kenney et al., 1995). Within a few years the commercial shipping industry boomed and since then their population has slowly been declining. Vanderlaan (2007) states that the number of commercial vessels on the water between the years of 1970 and 2000 has tripled and Silber (2010) agrees stating that the continued growth of the global freight transport is projected to grow at a rate of 4% or more through the year 2020. According to Shipping and World Trade (2017), the international shipping industry is responsible for over 90% of the worlds trade. Over 50,000 merchant ships trade internationally and come from more than 150 countries all over the world, shipping goods back and forth across international waters. The largest size of a vessel in 1956 was 137 meters (450 feet) and had a top speed of 18 knots (20 mph) (Rodrigue et al., 2017). By 2000 the vessels averaged a size of 340 meters (1,115 feet) and a top speed of 24 knots (27 mph) (Rodrigue et al., 2017). These vessels continue to increase in size and speed which creates a higher probability of strikes with the NARW.

The NARW has very specific migration patterns throughout the year within the Atlantic coastal waters. In the winter and fall months the NARW travels south to the waters off of the coast of Florida, Georgia, and South Carolina. During the winter breeding season, they prefer to breed in warmer, temperate waters (World Wildlife Fund, 2018). They also prefer to breed in the shallow, coastal waters categorized by NOAA, as nursing grounds. (North Atlantic Right Whale | NOAA Fisheries, 2018). In the spring and summer the NARW migrates north towards the coast of New England and the Bay of Fundy, located off the Southern end of Nova Scotia (North Atlantic Right Whale, 2018). This migration occurs due to an abundant food source and the have end of the the breeding season.  (World Wildlife Fund, 2018).

Within the NARW critical habitat areas are some of the countries most highly trafficked sea ports and shipping lanes. Of the top 20 seaports in the United States, twelve are on the east coast and four of those are in the critical habitats of the NARW.  The top 10 seaports in the world are stationed in New York/New Jersey, Georgia, Virginia, South Carolina, Florida, Maryland, Pennsylvania, and North Carolina. Among these top 10 eastern seaports, New York and New Jersey are the largest totaling 6,251,953 cargo containers aboard ships ranging from 135 meters to 307 meters in length (Top 10 U.S Container Ports, 2018). In critical habitat areas such as Cape Cod Bay, that overlap with the Boston Seaport, it is estimated that there several vessel movements a day during the months of December- May with four inbound or outbound vessels from Boston, and two from ports in the Gulf of Maine (Nichols & Kite-Powell, 2005).The Boston Harbor itself hosts 3500 ship trips a year, nearly 10 vessels coming in or out a day (Winter, 2009). These top 10 seaports overlap with the designated seasonal management areas from November 1 to April 30th, specifically the Port of New York and New Jersey, the Entrance to the Massachusetts Bay and entrances to Ports in North and South Carolina. (Reynolds III et al., 2006).  

Analyses of past right whale sightings have shown that such sightings are likely to indicate a group of feeding whales that will remain within 15 nmi of the initial sighting location for at least two weeks (Reynolds III et al., 2006).

 

The NARW tends to have higher incidence rates of vessel strikes when compared to other whale species due to their slow swimming speeds and their positive buoyancy (Silber et al., 2010). Their positive buoyancy can be attributed to gas filled cavities and a high percentage of buoyant tissues such as blubber (Nowacek et al., 2001). The positive buoyancy makes it difficult for the whale to dive quickly underneath the surface to avoid an incoming ship. This would be  comparable to pushing a beach ball underwater. The large beach ball inflated with air is very buoyant, making the force of the water push it up, and the beach ball stay close to the surface.

Vessel strikes with the NARW are also very common due to their susceptibility of hydrodynamic forces from passing ships. Hydrodynamic forces occur when forces are exerted from liquids in motion. The force created by ships draw the whales in, resulting in deadly collisions (Hydrodynamics, 2014). Many ships passing through the NARW critical habitats are large container ships, car carriers, and tankers (Knowlton et al., 1995). Knowlton (1995) states that these ships can range in size anywhere from 144 feet (43 meters) to 950 feet (290 meters). A study was performed with computer software where data such as ship measurements, whale measurements, speed, weight, water depth, etc were put in to model a practical whale and ship encounter. Data collected for three popular ship types passing through the critical habitats of the right whale were put into a database and a speed of 15 knots (17.2 mi/hr) was set as a constant. The two largest types of ships created a force large enough to cause a collision with the whale and create lacerations from the ships propellers (Knowlton et al., 1995). If the ships speeds were reduced to 10 knots (11.5 mi/hr), the hydrodynamic forces would be weaker and no collisions due to hydrodynamic forces would take place (Knowlton et al., 1995).

Commercial Shipping plays the largest role in the decline of the North Atlantic right whale population, as it is responsible for 53% of all death diagnosed by whale necropsies (Vanderlaan et al., 2009). With the North Atlantic Right Whale Population numbering only 300-400 individuals, the deaths caused by vessel strikes feel a significant impact as one whale death in a population

 

In 2008 the NOAA proposed a rule that would try and mitigate the whale and vessel strikes. Seasonal and Dynamic Management Areas were put in place to help reduce the number of vessel strikes with the NARW. Seasonal Management Areas (SMA’s) are highly populated NARW areas where mandated speed limits of 10 knots (11.5 mi/hr) or less are put in effect for commercial vessels greater than or equal to 65 ft (19.8 meters) in length (NOAA 2008). SMA’s are located based on right whale movement and distribution, vessel strike distribution, and predictable vessel traffic (Van der Hoop, 2015). The northernmost SMA’s occur during the spring and summer and include the Great South Channel, Race Point, and Cape Cod Bay (Laist et al., 2014). Following down the coast are the fall and winter SMA’s which include the Block Island Sound, New York Harbor, Delaware Bay, Chesapeake Bay, Morehead City, North Carolina/Georgia Coast, and Southeast U.S. Coast (Laist et al., 2014). Dynamic Management Areas (DMA) are 15 day voluntary speed limits for areas where right whale aggregations (groups) greater or equal to 3 are detected outside active SMA’s (Van der Hoop, 2015).

Since the implementation of these management areas there has been a significant decrease in whale mortalities. Between 2000-2006 there were on average 2 mortalities per year, but after the SMA’s were placed (2007-2012) it decreased to .33 mortalities per year (Van der Hoop et al., 2015). According to Van der Hoop (2015) vessel strike mortality in right whales has decreased inside the SMA’s but increased outside active SMA’s. DMA’s were put in place to try and lower the number of mortalities but vessels are not voluntarily slowing down or rerouting. Chion (2018) states that mitigation efforts must be enforced and regulated, rather than voluntary in order to successfully prevent NARW collisions. Voluntary efforts lack reliable data and the surveillance of voluntary mitigation efforts is indeed limited. While DMA’s have proven to be ineffective, SMA’s are very effective and have reduced the number of NARW mortalities with ship strikes dramatically.

Of all whale mortalities due to ship strikes, only about 56% have been inside the SMA’s. That means 44% of whale mortalities during the SMA periods are outside of the speed-limit protected zone (Van der Hoop et al., 2015). Schick (2009) states that the originally proposed 30 nautical miles (NM) (34.5 miles) buffer by NOAA in 2006 as compared to the current 20 NM (23 miles) buffer set by NOAA in 2008 would protect an additional 5959 square miles of NARW suitable habitats in the Mid-Atlantic Ocean. The NARW calving ground, a specific area where the whales give birth, has been found directly in or adjacent to major shipping lanes, which in turn can lead to increased collisions among young calves (Fujiwara et al., 2001). Specific shipping lanes in the Bay of Fundy and the Great South Channel have established seasonal areas to be avoided (ATBA) in order to protect and reduce the number of fatal strikes in the critical habitat for the NARW (Silber et al., 2010).

 

Proposal:

Extending the current SMA’s by 10 NM (11.5 miles) to the originally proposed 30 NM (32.5 miles) would reduce the number of vessel strike mortalities to the NARW.

Increasing the size of SMA’s will not have much of an economic impact on the shipping industry. Data was collected from 62,756 ships and Nathan Associates Inc. (2012) concluded that the average delay of all vessel types affected by SMA’s was 22 minutes. The total cost of SMA’s on vessels was $19.6 million for the year of 2009, which comes out to be about $313 per ship. Nearly 63% of this cost was from container ships. Even though this number does seem large, the US shipping industry makes about $183.3 billion per year according to World Shipping, which would make the cost of SMA’s on the shipping industry only .01% of its annual profit. This increased cost is from the oil needed to power ships with the adjusted speeds, so increasing the size of the SMA’s will have little effect on the shipping industry. Maine’s Lobsterman Association told the Bangor Daily News (2008) that they welcome the regulations, saying that fisheries and shipping industries should share the responsibility for protecting the whale. The only other way the shipping industry could be economically impacted by the SMA’s is if they do not adhere to the regulations set by the Seasonal Management Area. The National Oceanic and Atmospheric Administration (2008) can monitor the speeds of vessels using an Automatic Identification System (AIS) to determine when vessels exceed speed limits in the protected areas. If the vessels are found to be exceeding the limits they will be penalized anywhere from $11,000 to $100,000 and could possibly face time in prison, depending upon the number of times they have violated the SMA’s (NOAA, 2018).

Creating areas where strict vessel speed limits are enforced has been done previously and has been extremely successful when encompassing the animals critical habitat. This is true for the Florida Manatee, another species that has been threatened due to vessel strikes (Pittman C., 2018). Vessel speed restrictions in Manatee critical habitats was implemented by the U.S. Fish and Wildlife Service in the early 2000’s in Florida. This rule has caused boats to either slow their speeds or avoid these areas all together (Laist et al., 2006). After only a year of these restrictions in place, there was a significant drop in vessel related manatee deaths from 8 deaths the year earlier, to only 1 death, with only 9.2% of boat operators that were not in compliance with the speed limits (Laist et al., 2006). This data provides evidence that large  management zones with speed limits can drastically decrease the number of collisions due to vessel speeds, while also providing evidence that boat operators will adhere to the rules implemented.

The NARW faced nearly three centuries of whaling until its population was at an all time low and they have been struggling to recoup ever since. Commercial vessels have accounted for over half of the NARW deaths and are the biggest issue in their soon-to-be extinction. This is because commercial shipping became much more prominent after 1970 and the size and speed of the vessels have increased. The calving and feeding grounds of the whale are in high traffic shipping areas, which means there is a much higher probability that a strike will occur. The high buoyancy of the whale makes it hard for them to dive under vessels and makes them slow swimmers, making it difficult to get out of the way. Each NARW death impacts is detrimental to the population size, and SMA’s have been put in place to help reduce the mortality rate. It has been proven successful because the number of mortalities per year inside SMA’s prior to the rule and after the rule has dropped from 2 to 0.33. Extending the current SMA’s by 10 NM (11.5 miles) would help further decrease the vessel strike mortality rate of the NARW. 

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