Chceme-li však skoncovat s nadměrným rybolovem ve lhůtě, kterou jsme si stanovili, musíme své úsilí ještě zvýšit.

Could you please translate this to English?

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Still, we need to strengthen our efforts to end overfishing by the target date we have agreed.