Week 2 trip to the coast

Jan 8-13 2008 (Tuesday-Sunday):
We traveled by car from Windhoek to Henties Bay on the west coast, which took about 5 hours with just two brief stops (for gas and for Katie to pee in the desert) along the way. Alan drove slower than all but two large trucks (one carrying cows), but was still averaging over 100 kph on “tar roads” (paved) and slightly slower on the “salt road” along the coast.
The drive shows a gradient from semi-arid savannah to almost pure sand. We began in a now-familiar landscape dominated by acacia trees. The grasses in the ground cover seem entirely dry, but nevertheless were being collected in huge bags by groups of people along the road. We suspected they were using the grass as animal forage. We saw some goats, and a tannery/stock pens. Farther from Windhoek, we began to see “wild” animals as well, a few springbok, several troops of baboons, termite mounds, and warthogs. The distribution of termite mounds and warthogs seemed almost perfectly correlated, with a center around the “garden city” of Okahandjo, which must have a reliable water source to be able to grow olives and tomatoes. As we drove farther west, the grass in the understory turned to short brown tufts, and the acacia trees became smaller and sparser. Along the whole drive, we saw distant mountains, each set seemingly different in geology, based on color (from grey to red) and shape (from mounded to spikey). There were only two more sizable settlements along the way to the coast, at Karibib and Usakos, nestled in a large depression that must bring some water. After Usakos, the fences that had lined the highway throughout the rest of the trip dropped out, and we saw no more animals. Although the “rest” signs still showed a picnic table under a tree, instead these rest areas had a permanent awning – no trees available anywhere. As we approached Swakopmund, I finally understood how huge the landscape of Namibia appears, with an arcing blue sky and vast panorama of arid ground to the distant mountains: the ocean looked small in comparison! Probably the close curtain of fog over the ocean contributes. We turned north from Swakopmund, leaving behind us the enormous red dunes just to the south. On the beach side, we saw many restrooms, but the coast was quite deserted except for a few fishers with poles so long that they attach them for transport to the front bumper, sticking up in the air. On the far side of the road, which was still hard and flat despite no asphalt, we saw only one type of low-lying bush that accumulates sand into mounds. When we saw them up close later in the evening, the accumulated sand is riddled with animal burrows. The plants could be huge Salicornia, by the round succulent shape of stems and leaves. We also passed an area of salt-lichen, closed to off-road traffic. It appeared red-brown and quite large, maybe 10-20 cm aggregations, at least as we passed at speed and distance in the car.

When we arrived at the Sam Nujoma Marine Resources Research Center, we were welcomed into the Director’s suite, as the director had quit and left the day before. The center is 4 years old, and directors apparently have a difficult time dealing with its infrastructure challenges, low usage, and remote location. It’s actually quite a remarkable place: the architect designed the buildings at odd angles so they appear already to be crumbling off the sand cliff into the sea (perhaps that was not his intention), and an underground river has its mouth here, so freshwater is easily accessible from wells (there are small green lawns and numerous horticultural projects). In fact, the freshwater flow is so large that it leaves a small 2-m lens of saltwater on the surface, where all the marine organisms live. And the remainder of the water column along this stretch of coast is fresh and often anoxic. SaNuMaRC has delighted, surprised, and puzzled us. It was established with an elaborate plan of “closing the loop” to achieve sustainability, but the solar hot water heater is broken and water runs continuously, the biogas digester apparently doesn’t work because the septic truck came twice for pump-out, the horticultural plants include two notorious invaders of arid land (Opuntia and tamarisk), and the chicken, geese and ducks brought in for pest control have been caged (against hyenas and because they ate plants instead). We were also puzzled by the placement of the center: no thoughtful ecologist would have selected the place because of the low diversity on the exposed beach. No thoughtful lab scientist would have selected the place because there is no running seawater – despite 4 years of trying, it has been a recent breakthrough to establish a permanent pipe to fill carbuoys with “good” seawater at the bottom of the dune, then truck it to the top. Communication with the outside world is through UNAM’s network, which makes email decidedly slow (many minutes simply to load a web page) especially during weekdays when others are also on the network. Alan removed a bulb from a dissecting ‘scope with no plug to replace the burned-out bulb in the second ‘scope, allowing us to examine algae. The library mostly contains material about UNAM, with just a handful of reference books – although, given how little we know about natural history, the perfect number to get us started. We wondered what political decision was made to place the center in this remote location and invest so much in buildings rather than equipment to expedite science: then we found out that Sam Nujoma has a house just down the street in Henties Bay! Scientists and staff at the center bought fish for Nujoma and entourage; and Saturday near sundown the same vehicle returned with two loads of boxes that were put into the common room – possibly the empty, unplugged walk-in freezer (Alan had checked it out from curiosity earlier in the day). Mystery!

We have been impressed by many of the horticultural projects, especially growing different varieties of squashes and melons to look for resistance to salt spray (imagine! Watermelons growing out of sand!), and successful production of oyster mushrooms (these grow out of the end of plastic bags in a special room). Even with limited seawater, there are also projects to raise marine fish in tanks.

SaNuMaRC, like much of Henties Bay, perches above a restless ocean on a red-sand dune: the beach sand is gray, and the old river sand purple in places. This beach has some similarities to the one we left on the outer coast of Washington: extensive sand (for hundreds of miles, rather than tens) that people drive on (with Land Rovers and quad bikes rather than pick-ups). Signs all indicate that it is illegal to drive on beaches, but the enforcement is apparently lax. People drive 4x4 vehicles to set up elaborate day-camps for fishing and kite-flying; and they drive quad bikes up and down the steep sand cliffs that plunge 20-30 m to the beach. We observed that almost everyone driving on the beach was white, and we’ve heard people come from all over Africa because these beaches are some of the last remaining where it is possible to drive. Some of the roadside trash suggests that fireworks were set off over New Years as well.

We’re beginning to learn about the Namibian coast by walking the beaches at low tide. The beaches themselves are quite barren, reflecting the dynamic movement of sand – 1 m per week northward movement, and perpetual rearrangement of berms and slopes. One day, water was trapped in a high intertidal pool and Katie went swimming in comfortably warm water up to her thighs. The next day the pool simply drained away. We found just two species in the sand: sand-colored isopods up to nearly 1 cm in length, which nibbled on toes but burrowed rapidly in the sand, presumably food for the few shorebirds we’ve seen. And Donax surf clams – Pismo clams in California – that work their way up and down the beach in the swash. Alan traded a local fisherman some beach-cast tackle for information that the clams are quite rare near the marine station, but become more abundant a few km N and S where the sand quality changes. We found a few shells, some recently opened for bait, and two moribund individuals that allowed us to see internal anatomy: a large digger foot and two siphons, too small to make anything but bait or chowder.
The wrack on the beach is slightly richer, dominated by Laminaria kelp and a small 1-2 cm native mussel. Elsewhere, this Laminaria is collected for cultured abalone food, but it is probably too rare to grow much of a business: there’s just not sufficient hard substrate along the coast to support vast kelp forests. We also heard that the small native mussel is such an effective fouling organism that is preventing the expansion of Mytilus galloprovincialis from S. Africa north along this stretch of coastline. In the wrack we found two morphological types of larger mussels: one is quite elongate and brown, with an outer edge that is almost square in shape; the other is jet-black with a white-to-blue abraded umbo and sharp angle on the shell edge near the hinge – perhaps gallo. At the low, large patches of mussel shell rolled around in the surf, almost flowing like water up and down the beach. The wrack also included smaller numbers of: limpets, a translucent brown circular shell, snails, Venerupis clam shells, sea cucumbers, bryozoans – primarily one that forms long, narrow, flat colonial blades, crab carapaces, and parts of spiny lobsters. We have begun to look at some of the algae and have found, in addition to Laminaria pallida, ulvoids and Cladophora for greens, and numerous reds. Some look familiar, such as Plocamium and Ceramium, but some were really impossible to tell. We had two books at our disposal: some color plates and descriptions in the Seaweeds of southwest Africa, and line drawings in Branch and Branch’s guide to seashores. But the reds included some fascinating types, for instance one that appeared to have no holdfast but instead twined around Cladophora filaments, and another with dramatic flower-like reproductive structures emerging in patches from a flat blade. We did find one deadly species - Physalia (Portugese man-o-war), which blew in droves onto the beach as the wind shifted from NW to SW one afternoon. Alan collected a whole bucketful, along with the similarly-blue Velella velella (By-the-wind sailor), which is common on the beaches of Washington.

We’re also learning about the Namibian coast by talking with scientists: Larry Oellermann, who is on a multi-year contract at SaNuMaRC to improve mariculture, and several people at NatMIRC (National Marine something research center) in Swakopmund, the major research site for the Ministry of fisheries and marine resources. The Benguela system is one of permanent upwelling, not intermittent. Generally there are strong winds from the southwest (although mostly northwest during this stay), with occasional shifts to the east that bring terrible (to people) but dune-nourishing sand. Plus flies. The water was soupy green, even in the tidepool caught by sand, and the high-tide waves were frothy with diatoms. This sounds tremendous for marine production: Even here, however, wild finfisheries are collapsing (we heard that sardines are essentially gone, although the fish identification book in the library indicates they are now carefully managed and sustainably harvested! Offshore, orange roughy and Patagonian toothfish, both long-lived, slow-to-mature deepwater species, began to be exploited around 1995, and in just a few years catch per unit effort plummeted.) And last year 60% of the oyster crop was lost to sulfur “blooms”. The fishery and mariculture troubles probably have different causes, and interestingly sulfur appears entirely natural. High production in the coastal ocean contributes to a rain of organic material reaching the bottom, where it accumulates and is decomposed by such things as the largest bacterium ever discovered (1 mm cells!). Decomposition creates pockets of hydrogen sulfide that, for reasons yet unknown (at least 15 hypotheses have been suggested), occasionally bubble out over the course of a week or so: the hydrogen sulfide reacts with oxygen in the water column to create water and elemental sulfur. This elemental sulfur is visible in satellite imagery as an enormous patch of light-blue off of the coast. And locally it appears as anoxic water all the way to the surface: immediately bad for many fish and crabs, and intolerable by Pacific and European oysters after about a week (whether from the sulfide or anoxia is not clear). Some of the native species (a goby, mussels, clams) apparently last longer.