On 16 December 2017 the Two Oceans Aquarium released Yoshi the loggerhead turtle back into the ocean. Yoshi was the size of a dinner plate when she first arrived here, via a fishing boat, in 1997. Given Yoshi’s age, her excellent health, and her display of certain behaviours, it was decided that it is time for her to be released back into the ocean. Weighing 183kg, Yoshi was released 27 nautical miles south west of Hout Bay in 20.6°C water.
Where is Yoshi now?
Yoshi was fitted with a satellite tag and we’ll update you on her whereabouts right here, when and where we can.
16 March 2018
What an interesting few weeks since the last update! Yoshi is enjoying some ‘coastal living’ on the Namibian Coast – and we think that she is most likely having a jelly-feast. The Namibian coastline has seen various algal blooms contributing to large concentrations of jellies and fish, and even some orcas have been spotted in the Walvis Bay area last week. Yoshi is certainly stocking up while food is abundant, before the next leg of her epic journey!
- Yoshi has now been at sea for 90 days, and has clocked up a very impressive 2 540km. That is an average of 29km per day!
- Since our last update, she moved 175km north before turning towards the coast, around 5 March, and slowly making her way back to Walvis Bay, where she is currently swimming around, about 3.42km from shore. She, therefore, did a 380km loop over the last three weeks.
- She passed Henties Baai on 9 March, and was very close inshore. It took her two days to get to Swakopmund, and since 12 March she has been swimming around the Walvis Bay area.
- Her tag has logged 560 satellite passes with over 3 700 messages. We look at the number of messages per day because it actually gives us very interesting information. The tag transmits a message every time she surfaces (most likely whenever she pops up to breathe). This happens on average about 20 to 40 times per day. By looking at this information, we can establish that her swimming and breathing behaviour is well within a normal range.
We expected Yoshi to travel and explore for at least the first year after release, and she is clearly doing just that. Loggerhead turtles are found in all the oceans and there are nesting sites all around the world, so she could literally still go anywhere. See below the nesting sites for loggerheads:
It is exciting to wonder – where is she going next? Continuing back south? Or will she turn around and head back north? Right now we just know one thing for sure - she is having a jolly good ocean picnic!
25 February 2018
- Yoshi has now officially travelled just over 2 000 kilometres! (Yoshi has been heading towards warmer water, something we would like to be doing too.)
- She is about 150km west of Walvis Bay. Walvis Bay has a large industrial fishing port, and a lot of commercial fishing takes place in the vicinity. This includes hake, mackerel, pilchard, tuna and red crab fishing.
- Yoshi is covering good distances every day – and hopefully getting her share of pilchard along the way.
- She is maintaining her pace of about 29.3km per day, which is very impressive.
- The straight-line distance from release site is now approximately 1 400km.
- The water temperature has increased to about 20.4°C, which she's surely enjoying.
She is such an ocean trooper. Seventy days back in the ocean and swimming like a superstar.
18 February 2018
- Yoshi has been back in the ocean now for 64 days, and she is making great progress up the West Coast. She has travelled 1 860km already. She is currently about 130km offshore from the Hardap region of Namibia. She is actually in line with Sesriem – straight west, and heading towards Walvis Bay.
- We have seen 390 satellite passes.
- Yoshi’s straight line distance from her release site is now 1 224km at a heading of 336 degrees, which means she has done more than 600km of exploring along the way.
- Her average daily distance covered remains about 29.5 to 30.5km, which is really impressive.
- The water temperature is getting a bit warmer, and is a lovely, temperate 19.5 to 20°C at her current location.
- Her satellite tag sends a signal every time she surfaces.
- The ocean floor is at about 1 050m below surface – so she is in the proper deep and open ocean.
- Two months, two countries – only another 16 countries to go before she gets to loggerhead nesting sites at Cape Verde, off Senegal. I wonder whether she will settle at Cape Verde, or possibly cross the Atlantic and head for the nesting populations around the Bahamas, Florida and Mexico? Or will she venture to the Mediterranean Sea? Only time, and thousands of kilometres, will tell. Let’s hope we get satellite transmission for as long as possible.
Loggerhead sea turtles have two lineages, which diverged approximately 3 million years ago: one in the Indian and Pacific Ocean basins, and the other in the Atlantic Ocean and Mediterranean Sea. There have been two effective transfers of matrilines between the groups, likely through the waters around South Africa. These rare events have been sufficient to prevent the two lineages from developing into separate species (Bowen 2003; Bowen and Karl 2007).
Yoshi is swimming strongly and doing well. What an adventure.
6 February 2018
- Yoshi is currently about 131km west of Lüderitz, Namibia – so she has made some very good headway over the last week.
- She swam a very impressive 56km on 2 February! She has now travelled about 1 533km up the west coast of Africa.
- She swims 29km per day on average. As mentioned, her longest day thus far was 56km, with the shortest distance travelled on a day being 3.5km on the last day of the year (she started her New Year’s Eve party rather early, we imagine).
- Her average swimming speed is currently 1.21km per hour – which is perfectly within the normal range for loggerheads (wild and released).
- Water temperature where she finds herself at the moment is a very acceptable 18.5°C.
- Yoshi’s straight-line distance from her release site is 963km’s at a heading of 333 degrees (NNW). This basically means that if you were in a boat and used your GPS to direct you on a straight-line at 333°, you would find Yoshi after travelling for 963km’s (which is about 520 nautical miles). She, of course, spent quite a bit of time exploring Cape Town waters and the coastline – with two visits rather close to shore (2km and 6km offshore) - compared to her current 130km offshore position, and that is why her total distance travelled is significantly more than the straight-line distance.
- The Namibian coastline is rather long, so at her current pace it could take her another two months before moving into the warmer waters off Angola. There are various seamounts along the way, which offer fantastic feeding grounds, and knowing Yoshi, we are sure she will head over to these for some feasting (not sure "fasting" is in her vocabulary).
- From the data received, we can conclude that Yoshi is indeed a superhero and doing very well. She has been out at sea for 53 days already, with the two-month mark fast approaching. We are very relieved that she has safely navigated her way through various fishing grounds.
- We are so proud of this amazing turtle.
28 January 2018
- Yoshi had her "passport" stamped on 26 January when she left South Africa and entered Namibian waters! Currently, she is about 71km northwest of the Orange River, and about 15km offshore in very nice 19°C water with a depth of about 113m.
- She travelled about 30km over the last 24 hours – definitely looking strong.
- Her average distance per day has reduced slightly to 27km, mainly due to a few days hanging out closer inshore, most likely feeding. She has covered a total distance of 1 233km over the last 43 days.
- Her swimming speed is 1.19km per hour – which is well within the normal range for wild as well as released loggerhead turtles.
- We have seen 276 satellite passes.
- She is now 731km at a 341° heading (north-northwest) from her release site – that is the straight-line distance.
- What a champ.
16 January 2018
- Yoshi was released a month ago and is well on her way to Namibian waters.
- She is currently about 65km west of Hondeklipbaai, in 18°C water. She travelled just over 36km over the last 24 hours, and is thus making good progress.
- Her daily average distance travelled since release is just over 31km, which is a very respectable 1.3km/hour mean swimming speed. This compares well with swimming-speed data of wild loggerhead turtles as well as other rehabilitated and released loggerhead turtles that have been tagged.
- We have seen a total of 208 satellite passes during the last month of tracking and she is heading towards a total swimming distance of 1 000km!
- The straight-line distance from release site to current position is just short of 500km, and her heading from release site is at 342°.
- Yoshi is, and will be, moving through areas with commercial fisheries. She has already navigated past various tuna and hake longline areas, as well as demersal trawl areas. These are just some of the threats that all turtles face out at sea! She would have encountered on both sides of our coastline – with the West Coast having slightly more offshore fisheries than the East Coast, she is actually a bit safer (clever Yoshi).
- It took Winston, the rehabilitated and released hawksbill turtle, exactly two months to swim from release site off Cape Point to Hondeklipbaai early in 2016. Yoshi is on the move and doing well.
11 January 2018
Yoshi has travelled a very impressive 876km since her release on 16 December. She continued to head up the West Coast and by 5January she was about 80km west of Elandsbay. The water was a very respectable 18 - 19.5°C.
She passed Doringbaai on 7 January and started to move much closer to shore. We believe she spent a day or two feeding about 2.5km from shore, well north of Doringbaai, before heading back offshore yesterday.
She is about 85km northwest of the Olifantsriver mouth, with water temperature closer to 17°C now. If she continues in a northwesterly direction she will quickly get to warmer 19°C water.
She has averaged 32km/day since release, with the longest distance thus far in one day being 54km, and the shortest distance still the 3.5km over New Year's Eve.
We have seen 186 satellite passes since release.
Loggerhead sea turtles are globally distributed – she could literally still go anywhere, however, it seems as if she is about to head towards the Northern Cape at the moment.
3 January 2018
- Yoshi has made some good progress over the last few days, moving approximately 184km up the West Coast.
- She is currently about 100km west of Cape Columbine in a very mild water temperature ranging between 18.5 to 19.6°C.
- It seems as if she celebrated the New Year relaxing offshore, as she only travelled about 3.5km between 31 December and 1 January. However, her average daily travelling distance is currently 31.3km.
- She covered a distance of 34.6km over the last 24 hours, so she is going nice and strong.
- Total distance travelled since release is 594km.
- We have seen 127 satellite passes since the start of her journey.
28 December 2017
- Yoshi is definitely still exploring offshore Cape Town.
- We have received 77 satellite pings from Yoshi and she has travelled a total of 410km since release 12 days ago.
- She is currently in nice 19.6°C water, about 88km south west of Saldanha and about 94km north west of Cape Town. This is also 109km-long straight line from her release site.
- At this point in time, she is swimming strongly, averaging just over 40km/day over the last two days, but with a daily average of about 35km/day since release.
- She has moved against the southeasterly wind again, which is a very good sign that she is feeling strong.
- She is clever – hugging the warmer water!
- Yoshi has done a good roundabout and we believe it will take a few weeks for her to decide where she will finally head off to.
22 December 2017
- Yoshi seems to be exploring the Atlantic Ocean at the moment. Since 18 December, she has moved in a northerly direction and covered about 61km before veering west.
- She is staying nice and close to warmer water, finding herself in 19°C water at the moment.
- She has travelled a total distance of 205km since release, a solid 41km/day!
- We have received approximately 30 transmissions.
19 December 2017
- At 04:50 on 17 December we received our first location transmission. Yoshi had moved 30km to the east, and was south of Cape Point.
- She then decided to head back in a westerly direction and travelled about 64km before turning around and moving another 24km east. She is now approximately 16km south west of her release site and a good 37 nautical miles off Hout Bay.
- She has surfaced regularly (we know this as the satellite tag only transmits when she surfaces and it is in the line of view of satellites), which is a good indication of regular breathing.
- She also moved up-wind frequently, meaning she’s swimming strongly.
- As this point in time, we are still not quite sure whether she will be heading up the east coast or west coast. She has moved a bit further offshore, closer to even-warmer water.
- She is currently in the same area that Otto the hawksbill turtle was during the first few days after her release.