Put like that it sounds like a planning error. But the two activities have coexisted for over sixty years, and understanding why explains a good deal about how this piece of coast works.
Both are here for the same physical reason: a shallow, sheltered lagoon of very salty water, on the edge of a desert where it almost never rains.
01 Thirty-three thousand hectares of ponds
The saltworks was set up in 1957 to supply salt to the western United States, taking advantage of the lagoon's strong salinity. Around it grew a town of some thirteen thousand people that exists for that and for nothing else.
The process is utterly simple: seawater is pumped into concentration ponds, the sun and the wind are left to do the rest and the salt that remains is collected. The ponds cover 33,000 hectares, and production is around seven million tonnes a year.
Hence the scene you see from the road: enormous trucks hauling tippers loaded with white over white causeways, between sheets of brine that, depending on concentration and the micro-organisms living in it, turn pink.
Seven million tonnes a year come from leaving the sea in the sun somewhere it almost never rains.
02 Why the salt comes out precisely here
A solar saltworks needs three things: seawater at hand, flat ground and very little rain. Here all three come together with a generosity hard to match anywhere else in the world.
The lagoon began as a pocket beach on the coastal plain when sea level was some twelve metres lower than today's. Tides opened inlets and sediment gradually built a barrier that closed the whole thing off: hence shallow, wide and sheltered.
Then there is the climate. Along this band the desert reaches the shore and annual rain is measured in tens of millimetres, so evaporation always wins and salinity rises by itself. What on other coasts would be a problem is here the raw material.
03 Eleven thousand kilometres to give birth
The gray whale makes the longest migration known in any mammal. Each October it leaves the Bering and Chukchi seas and comes south for two or three months to these lagoons, between 8,000 and 11,000 kilometres one way.
It travels day and night, at some 8 kilometres an hour, covering on the order of 120 a day. The round trip adds up to between 16,000 and 22,000 kilometres, and it is repeated every year by an animal up to 15.2 metres long weighing between 41 and 45 tonnes.
And it comes to a place with no food. The lagoons are not a larder but a maternity ward: shallow, warm water sheltered from swell and predators, exactly what a newborn calf needs. The eating is done up north.
04 From hunting ground to sanctuary
The lagoon's history has a brutal turning point. In December 1857 a whaler first took his ship inside to hunt there, and on that first campaign he took twenty animals. He came back the next winter with more ships.
The logic was that of the shortcut: in open sea a whale is hard to find; in a closed lagoon, with mothers and calves inside, it is not. The population was left on the brink of disappearing, and the same man who led those campaigns later wrote one of the first scientific descriptions of the species.
The turn came in the 20th century. The biosphere reserve was created in 1988 and covers 24,930 square kilometres, the country's largest protected area; the lagoon has also been a Ramsar site since 2004 and forms part of a sanctuary listed as world heritage. The same water, the opposite use.
05 A coexistence that has been argued over
It would be convenient to tell this as a neat example of industry and nature in harmony, but it is not. The process leaves a residue, a very concentrated brine known as bittern, which is returned to the lagoon.
In December 1997, 94 green turtles were found dead weeks after a discharge of that residue, and the analyses found fluoride concentrations sixty times higher than in seawater. The company had maintained that the residue was merely concentrated seawater.
Telling it takes nothing away from the sanctuary and does not make the saltworks a textbook villain: it is simply what there is. Two intensive uses of the same body of water, with regulation that has tightened episode by episode.
06 What to look for if you go
First, the colour of the water. In the ponds you will see everything from pale green to intense pink, and that gradient is not decorative: it marks salt concentration and the organisms that survive at each stage. It is a chemical map in the open air.
Second, the whales' skin. The pale patches covering their heads and backs are not pigmentation: they are barnacles and attached crustaceans, and how many an animal carries says a good deal about its age and its routes.
And third, the calendar. Trips run under permit and in season, between December and April, centred on February. Outside those months the lagoon is still there, but empty: you will see saltworks, birds and desert, which is not nothing either.
