(Bloomberg Gadfly) — Here's some good news for the hard-pressed shipping industry: Of the top 15 container lines that were in operation nine months ago, four have gone out of business or are in the process of doing so.

Here's some not-so-good news: The global container fleet is still getting bigger.

The world's seventh-largest container line, Korea's Hanjin Shipping, filed for receivership last week. APL, operated by Singapore's Neptune Orient, was gobbled up by CMA CGM earlier this year in the industry's biggest takeover since 2005. Hapag-Lloyd is in the process of a merger with United Arab Shipping and China's two biggest state-owned container fleets have been combined to create Cosco Container.

Unfortunately, all that dealmaking on its own does little more than change the owner's or charterer's name on a ship register. What the industry needs is either more trade, or fewer ships.

Container shipping is certainly getting more concentrated than it was. Assuming the Hapag-Lloyd-UASC merger goes through and Hyundai Merchant picks up Hanjin's fleet, as Korea's financial regulator has suggested, then the top six shipping lines will have gone from controlling about 53% of the global fleet to 63%, according to Alphaliner, a shipping data service.

That shift to a less competitive market ought to provide some help in lifting container rates — especially as all of the top 10 fleets with the exception of Hamburg-Sued are now members of one of three shipping alliances, which together encompass about 80% of global vessels.

The problem for lines is that reduced competition hasn't been enough to juice container rates back into positive territory. Even after rebounding from their low of $666 per 40-foot box earlier this year, the benchmark rate for shipping a container on major routes remains stubbornly below costs that even market leader Maersk struggles to get below $2,000.

There's simply not enough trade going on to fill all the ships on the ocean. The value of global goods exports touched its lowest level in six years in February and has been running at subdued levels all year, according to the International Monetary Fund. Container volumes can be assumed to be going in roughly the same direction:

As a result, about a fifth of the global container fleet is sitting at anchor, up from less than 8% in trade's heyday ahead of the 2008 financial crisis. Hanjin's entire fleet is currently marooned offshore, as ports won't accept its ships at dock for fear that the company will be unable to pay shore fees or will have its assets seized by creditors, Bloomberg's Sohee Kim and Kyunghee Park reported Wednesday.

Shipping lines have two main options to survive this hurricane. They can sit tight, hope their debts don't overwhelm them in the way that Hanjin's and Hyundai Merchant's have done, and trust that trade will eventually recover and start filling their holds again. But that's a high-stakes bet, given the rise in protectionist measures in major economies, the U.K.'s vote this year to leave the EU, and a U.S. presidential campaign in which both candidates have voiced opposition to some trade deals.

The shorter route back to profitability will be to reduce the size of the fleet by turning some of those excess ships into scrap metal — but that will take a while. Low scrap prices make demolition a less attractive option these days, and in the meantime new vessels ordered before the current crisis are still being delivered, adding to the glut.

While the volume of container ships being broken up has risen sharply this year, the total fleet still managed to rise above 20 million 20-foot equivalent units for the first time in history in July, according to Clarksons Research. Turning round a big box ship is a slow process. Turning round the global container fleet will take even longer.

The views and opinions expressed in this post are the author’s and not necessarily those of WorkBoat.

Bloomberg Gadfly by David Fickling and Rani Molla. Fickling is Gadfly columnist covering commodities, as well as industrial and consumer companies. Molla is Rani Molla is a Bloomberg Gadfly columnist using data visualizations to cover corporations and markets. This column does not necessarily reflect the opinion of Bloomberg LP and its owners.