{"id":946,"date":"2016-09-20T20:47:50","date_gmt":"2016-09-20T20:47:50","guid":{"rendered":"http:\/\/blogs.oregonstate.edu\/gemmlab\/?p=946"},"modified":"2016-09-20T21:59:00","modified_gmt":"2016-09-20T21:59:00","slug":"oceanus-day-three-dolphin-delights","status":"publish","type":"post","link":"https:\/\/blogs.oregonstate.edu\/gemmlab\/2016\/09\/20\/oceanus-day-three-dolphin-delights\/","title":{"rendered":"Oceanus Day Three: Dolphin Delights"},"content":{"rendered":"

by Florence Sullivan, MSc student<\/p>\n

Our third day aboard the Oceanus began in the misty morning fog before the sun even rose. We took the first CTD cast of the day at 0630am because the physical properties of the water column do not change much with the arrival of daylight. Our ability to visually detect marine mammals, however, is vastly improved with a little sunlight, and we wanted to make the best use of our hours at sea possible.<\/p>\n

<\/a>
Randall Munroe www.XKCD.com<\/figcaption><\/figure>\n

Our focus on day three was the Astoria canyon \u2013 a submarine feature just off the Oregon and Washington coast<\/a>. Our first oceanographic station was 40 miles offshore, and 1300 meters deep, while the second was 20 miles offshore and only 170 meters deep.\u00a0 See the handy infographic below to get a perspective on what those depths mean in the grand scheme of things. \u00a0From an oceanographic perspective, the neatest finding of the day was our ability to detect the freshwater plume coming from the Columbia River at both those stations despite their distance from each other, and from shore! Water density is one of the key characteristics that oceanographers use to track parcels of water as they travel through the ocean conveyor belt<\/a>. Certain bodies of water (like the Mediterranean Sea, or the Atlantic or Pacific Oceans) have distinct properties that allow us to recognize them easily. In this case, it was very exciting to \u201csea\u201d the two-layer system we had gotten used to observing overlain with a freshwater lens of much lower salinity, higher temperature, and lower density. This combination of freshwater, saltwater, and intriguing bathymetric features can lead to interesting foraging opportunities for marine megafauna \u2013 so, what did we find out there?<\/p>\n

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Click through link for better resolution: Randall Munroe www.XKCD.com\/1040\/large<\/a><\/figcaption><\/figure>\n

Morning conditions were almost perfect for marine mammal observations \u2013 glassy calm with low swell, good, high, cloud cover to minimize glare and allow us to catch the barest hint of a blow\u2026.. it should come as no surprise then, that the first sightings of the day were seabirds and tuna!<\/p>\n

\"I<\/a>
I didn’t catch any photos of the tuna, so here’s some sunfish we spotted. photo credit: Florence Sullivan<\/figcaption><\/figure>\n

One of the best things about being at sea is the ability to look out at the horizon and have nothing but water staring back at you. It really drives home all the old seafaring superstitions about sailing off the edge of the world.\u00a0 This close to shore, and in such productive waters, it is rare to find yourself truly alone, so when we spot a fishing trawler, there\u2019s already a space to note it in the data log.\u00a0 Ships at sea often have \u201cfollower\u201d birds – avians attracted by easy meals as food scraps are dumped overboard. Fishing boats usually attract a lot of birds as fish bycatch and processing leftovers are flushed from the deck. \u00a0The birders groan, because identification and counts of individuals get more and more complicated as we approach other vessels.\u00a0 The most thrilling bird sighting of the day for me were the flocks of a couple hundred fork-tailed storm petrels<\/a>.<\/p>\n

\"Fork-tailed<\/a>
Fork-tailed storm petrels. photo credit: Florence Sullivan<\/figcaption><\/figure>\n

I find it remarkable that such small birds are capable of spending 80% of their life on the open ocean, returning to land only to mate and raise a chick. Their nesting strategy is pretty fascinating too \u2013 in bad foraging years, the chick is capable of surviving for several days without food by going into a state of torpor. (This slows metabolism and reduces growth until an adult returns.)<\/p>\n

Just because the bird observers were starting to feel slightly overwhelmed, doesn\u2019t mean that the marine mammal observers stopped their own survey.\u00a0 The effort soon paid off with shouts of \u201cWait! What are those splashes over there?!\u201d That\u2019s the signal for everyone to get their binoculars up, start counting individuals, and making note of identifying features like color, shape of dorsal fin, and swimming style so that we can make an accurate species ID. The first sighting, though common in the area, was a new species for me \u2013 Pacific white sided dolphins!<\/p>\n

\"Pacific<\/a>
A Pacific white sided dolphin leaps into view. photo credit: Florence Sullivan. Taken under NMFS permit 16111 John Calambokidis<\/figcaption><\/figure>\n

A pod of thirty or so came to ride our bow wake for a bit, which was a real treat. But wait, it got better! Shortly afterward, we spotted more activity off the starboard bow.\u00a0 It was confusing at first because we could clearly see a lot of splashes indicating many individuals, but no one had glimpsed any fins to help us figure out the species. As the pod got closer, Leigh shouted \u201cLissodelphis<\/em>! They\u2019re lissodelphis<\/em>!\u201d\u00a0 We couldn\u2019t see any dorsal fins, because northern right whale dolphins<\/a> haven\u2019t got one! Then the fly bridge became absolute madness as we all attempted to count how many individuals were in the pod, as well as take pictures for photo ID. It got even more complicated when some more pacific white sided dolphins showed up to join in the bow-riding fun.<\/p>\n

\"Northern<\/a>
Northern right whale dolphins are hard to spot! photo credit: Florence Sullivan Taken under NMFS permit 16111 John Calambokidis<\/figcaption><\/figure>\n

All told, our best estimates counted\u00a0about 200 individuals around us in that moment. The dolphins tired of us soon, and things continued to calm down as we moved further away from the fishing vessels.\u00a0 We had a final encounter with an enthusiastic young humpback who was breaching and tail-slapping all over the place before ending our survey and heading towards Astoria to make our dock time.<\/p>\n

\"Humpback<\/a>
Humpback whale breach. photo credit: Florence Sullivan. Taken under NMFS permit 16111 John Calambokidis<\/figcaption><\/figure>\n

As a Washington native who has always been interested in a maritime career, I grew up on stories of The Graveyard of the Pacific<\/em>, and how difficult the crossing of the Columbia River Bar<\/a> can be. Many harbors have dedicated captains to guide large ships into the port docks.\u00a0 Did you know the same is true of the Columbia River Bar?\u00a0 Conditions change so rapidly here, the shifting sands of the river mouth make it necessary for large ships to receive a local guest pilot (often via helicopter) to guide them across.\u00a0 The National Motor Lifeboat School<\/a> trains its students at the mouth of the river because it provides some of \u201cthe harshest maritime weather conditions in the world<\/a>\u201d. \u00a0Suffice it to say, not only was I thrilled to be able to detect the Columbia River plume in our CTD profile, I was also supremely excited to finally sail across the bar.\u00a0 While a tiny part of me had hoped for a slightly more arduous crossing (to live up to all the stories you know), I am happy to report that we had glorious, calm, sunny conditions, which allowed us all to thoroughly enjoy the view from the fly bridge.<\/p>\n

\"Cape<\/a>
Cape Disappointment Lighthouse at the Columbia River Bar.<\/figcaption><\/figure>\n

Finally, we arrived in Astoria, loaded all our gear into the ship\u2019s RHIB (Ridged Hulled Inflatable Boat), lowered it into the river, descended the rope ladder, got settled, and motored into port. We waved goodbye to the R\/V Oceanus, and hope to conduct another STEM cruise aboard her again soon.<\/p>\n

Now if the ground would stop rolling, that would be just swell.<\/p>\n

Last but not least, here are the videos we promised you in Oceanus Day Two<\/a>\u00a0– the first video shows the humpback lunge feeding behavior, while the second shows tail slapping. Follow our youtube channel for more cool videos!<\/p>\n